Stilbite crystals, however, appear to be almost orthorhombic, and a larger unit cell can be chosen, containing two formula units (Z = 2) such that resembles an orthorhombic cell, with all three crystal axes very nearly mutually perpendicular. The mineral is said to be pseudo-orthorhombic. Non- endmember forms of stilbite may be triclinic or even truly orthorhombic, indeed the framework can have symmetry ranging from orthorhombic to triclinic in a single crystal.
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At 75 GPa it changes to a face-centered orthorhombic structure. At 100 GPa it changes to a body centered orthorhombic monatomic form.
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For orthorhombic, tetragonal and cubic lattices with as well, then :V = a b c .
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Fleischer, M. (1970) New mineral names. American Mineralogist, 55, 533. Marthozite is orthorhombic, meaning that it has three axes of unequal lengths all orthogonal to each other. Since it is orthorhombic, marthozite is biaxial, meaning that it has three different indices of refraction.
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Its crystal symmetry was first assigned as orthorhombic, then as monoclinic, and finally as triclinic.
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Strontium aluminates exist in other compositions including SrAl4O7 (monoclinic), Sr3Al2O6 (cubic), SrAl12O19 (hexagonal), and Sr4Al14O25 (orthorhombic).
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Superconductivity disappears at x ≈ 0.6, where the structural transformation of YBCO occurs from orthorhombic to tetragonal.
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As determined by X-ray crystallography, both polymorphs, tetragonal and orthorhombic feature a pyramidal four-coordinate lead center. In the tetragonal form the four lead–oxygen bonds have the same length, but in the orthorhombic two are shorter and two longer. The pyramidal nature indicates the presence of a stereochemically active lone pair of electrons. When PbO occurs in tetragonal lattice structure it is called litharge; and when the PbO has orthorhombic lattice structure it is called massicot.
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Silver selenide has two crystal phases. At lower temperatures, it has an orthorhombic structure, β-Ag2Se. This orthorhombic phase, stable at room temperature, is a Narrow-gap semiconductor, with space group P212121. The exact size of the band gap has been given variously from 0.02 eV to 0.22 eV.
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Massicot is lead (II) oxide mineral with an orthorhombic lattice structure. Lead(II) oxide (formula: PbO) can occur in one of two lattice formats, orthorhombic and tetragonal. The tetragonal form is called litharge. PbO can be changed from massicot to litharge (or vice versa) by controlled heating and cooling.
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Natural thallium(I) iodide was only recently found, as a orthorhombic polymorph called nataliyamalikite. It is of a fumarolic origin.
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Leightonite forms flattened to elongated bladed crystals of variously interpreted crystal structure. Its crystal system is reported as triclinic morphologically, but also as pseudo-orthorhombic due to intricate lamellar twinning that mimics orthorhombic symmetry. Because it is triclinic, the crystal is represented by a system of three unequal vectors with corresponding unequal angles between them.
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On cooling from high temperature, KNbO3 undergoes a series of structural phase transitions. At 435 °C, the crystal symmetry changes from cubic centrosymmetric (Pmm) to tetragonal non-centrosymmetric (P4mm). On further cooling, at 225 °C the crystal symmetry changes from tetragonal (P4mm) to orthorhombic (Amm2) and at −50 °C from orthorhombic (Amm2) to rhombohedral (R3m).
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Several polymorphs of rubrene are known. Crystals grown from vapor in vacuum can be monoclinic, triclinic,Akopyan, S. A.; Avoyan, R. L. and Struchkov, Yu. T. Z. Strukt. Khim. 3, 602 (1962) and orthorhombic motifs. Orthorhombic crystals (space group Bbam) are obtained in a closed system in a two-zone furnace at ambient pressure.
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Caesium tungstate forms colorless crystals, which are strongly hygroscopic. A phase transition from orthorhombic to hexagonal crystal system occurs at 536 ℃.
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Reinerite is a rare arsenite (arsenate(III)) mineral with chemical formula Zn3(AsO3)2. It crystallizes in the orthorhombic crystal system.
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Libethenite almost always takes the form of dark-green orthorhombic crystals. It is often found in clusters with other libethenite crystals.
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The uranates include NiU2O6, NiUO4 α and β forms (orthorhombic a=6.415 Å; b=6.435 Å; c=6.835 Å), and NiU3O10.
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Bornite, also known as peacock ore, is a sulfide mineral with chemical composition Cu5FeS4 that crystallizes in the orthorhombic system (pseudo- cubic).
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This structure is based upon the crystal structure of the complex between 2 human nonsense mediated decay factors, upf1 and upf2, orthorhombic form.
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WB2 has the same hexagonal structure as most diborides (AlB2, MgB2, etc.). WB has several forms, α(tetragonal), β (orthorhombic) and δ (tetragonal).
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Macdonaldite crystallises in the orthorhombic system. Macdonaldite is anisotropic with low relief.Bloss, F.D. (1999) Optical Crystallography. Mineralogical Society of America, 5, 161-163.
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Prismatine is an orthorhombic-dipyramidal mineral containing aluminium, boron, fluorine, hydrogen, iron, magnesium, oxygen, and silicon. It forms a solid solution series with kornerupine.
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Olivine has an orthorhombic structure with a space group of Pbnm.Brown George. "A structural Study of Iddingsite from New South Wales, Australia". American Mineralogist.
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Molybdite is the naturally occurring mineral form of molybdenum trioxide MoO3. It occurs as yellow to greenish needles and crystallizes in the orthorhombic crystal system.
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Paramontroseite (V4+O2) is a relatively rare orthorhombic vanadium oxide mineral in the Ramsdellite group. Synthetic paramontroseite may have applications in medicine, batteries and electronics.
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MgCu2 can react with boron or its oxide to form magnesium borides. It can also react with magnesium hydride to produce orthorhombic Mg2Cu, liberating hydrogen.
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Lead(II) fluoride is the inorganic compound with the formula PbF2. It is a white solid. It exists as both an orthorhombic and cubic forms.
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Krennerite is an orthorhombic gold telluride mineral which can contain variable amounts of silver in the structure. The formula is AuTe2, but specimen with gold substituted by up to 24% with silver have been found ([Au0.77Ag0.24]Te2). Both of the chemically similar gold-silver tellurides, calaverite and sylvanite, are in the monoclinic crystal system, whereas krennerite is orthorhombic. The color varies from silver-white to brass- yellow.
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Typically, substances with the perovskite structure show lower symmetry, owing to the distortion of the crystal lattice and silicate perovskites are in the orthorhombic crystal system.
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Salzburgite has a general empirical formula of Pb2Cu2Bi7S12 and an orthorhombic crystal structure.Ralph, Joylon, and Ida Chau. Salzburgite. Joylon Ralph, 1993-2010. Web. 14 September 2010.
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Rh2O3 has been found in two major forms. The hexagonal form adopts the corundum structure. It transforms into an orthorhombic structure when heated above 750 °C.
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It has a vitreous lustre with a white streak, and is brown or yellow in color. It has a conchoidal, uneven fracture, and an orthorhombic crystal system.
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The narrower, modern scientific definition for marcasite as orthorhombic iron sulfide dates from 1845. The jewelers’ sense for the word “marcasite” pre-dates this 1845 scientific redefinition.
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Pinalite is a rare lead tungstate–chloride mineral with formula: Pb3WO5Cl2. Pinalite crystallizes in the orthorhombic crystal system.Clark, A.M. (1993) Hey's Mineral Index (Third edition). 548 p.
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In crystallography, the orthorhombic crystal system is one of the 7 crystal systems. Orthorhombic lattices result from stretching a cubic lattice along two of its orthogonal pairs by two different factors, resulting in a rectangular prism with a rectangular base (a by b) and height (c), such that a, b, and c are distinct. All three bases intersect at 90° angles, so the three lattice vectors remain mutually orthogonal.
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The primitive cell contains two formula units of aluminium oxide. Aluminium oxide also exists in other, metastable, phases, including the cubic γ and η phases, the monoclinic θ phase, the hexagonal χ phase, the orthorhombic κ phase and the δ phase that can be tetragonal or orthorhombic. Each has a unique crystal structure and properties. Cubic γ-Al2O3 has important technical applications. The so-called β-Al2O3 proved to be NaAl11O17.
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Ruthenium diboride was first thought to have a hexagonal structure,C. P. Kempter and R. J. Fries "Crystallography of the Ru-B and Os-B Systems" J. Chem. Phys. 34, 1994 (1961) as in rhenium diboride, but it was later tentatively determined to possess an orthorhombic structure.R. B. Roof, Jr. and C. P. Kempter "New Orthorhombic Phase in the Ru-B and Os-B Systems" J. Chem. Phys.
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The PbO can be changed from massicot to litharge or vice versa by controlled heating and cooling.A simple example is given in A more complex example is in The tetragonal form is usually red or orange color, while the orthorhombic is usually yellow or orange, but the color is not a very reliable indicator of the structure. The tetragonal and orthorhombic forms of PbO occur naturally as rare minerals.
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Anhydrite, or anhydrous calcium sulfate, is a mineral with the chemical formula CaSO4. It is in the orthorhombic crystal system, with three directions of perfect cleavage parallel to the three planes of symmetry. It is not isomorphous with the orthorhombic barium (baryte) and strontium (celestine) sulfates, as might be expected from the chemical formulas. Distinctly developed crystals are somewhat rare, the mineral usually presenting the form of cleavage masses.
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Guanidinium chloride crystallizes in orthorhombic space group Pbca. The crystal structure consists of a network of guanidinium cations and chloride anions linked by N–H···Cl hydrogen bonds.
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The molecule is tetrahedral, as predicted by VSEPR theory. The a Se–O bond length is 161 pm. In the solid state, it crystallizes in an orthorhombic structure.
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Natrophilite is a mineral with the chemical formula NaMnPO4. In a pure form it has a yellow coloration. Its crystals are orthorhombic to dipyramidal. It is transparent to translucent.
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Otwayite, Ni2CO3(OH)2, is a hydrated nickel carbonate mineral. Otwayite is green, with a hardness of 4, a specific gravity of 3.4, and crystallises in the orthorhombic system.
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The 2/m symmetry group indicates a two-fold axis with a perpendicular mirror plane. Grandreefite was originally classified as an orthorhombic mineral but was determined monoclinic instead upon further analysis. Pseudograndreefite, one of three other newly discovered minerals in 1989 at the Grand Reef Mine site, has orthorhombic crystallography. Optically, grandreefite is an anisotropic mineral, meaning the velocity of light varies depending on the direction through which it is passing through the mineral.
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Changbaiite (PbNb2O6) is a member of the oxide mineral class in which the mineral contains oxygen which is grouped along with one or two metal ion. Changbaiite is classified as a multiple Oxide XY2O6 and it generally has an ionic bond. Furthermore, it is also orthorhombic at a temperature of 25 °C and it changes to orthorhombic-tetragonal at 570 °C.Subbarao, E. C., and Shirane, G. (1960) "Nonstoichiometry and Ferroelectric Properties of PbNb2O6-Type Compounds".
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Aguilarite is part of the acanthite-like solid solution series Ag2S–Ag2S0.4Se0.6. The mineral comprises the range from 50 atomic percent selenium up to the transition from monoclinic to orthorhombic.
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1963, vol. 16, pp. 385-389. :Conversion of orthorhombic to monoclinic metaboric acid. Above 140 °C, boric acid or the other forms of metaboric acid convert to cubic metaboric acid.
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A number of other structure types can also be adopted, with varying electrical properties: cubic, tetragonal I and hexagonal phases are metallic, whereas orthorhombic and tetragonal II structures are semiconducting.
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Perite belongs to the Orthorhombic crystal system, and has the properties of 2/m 2/m 2/m crystal class. Therefore, perite has 3 mirror planes and 3 twofold rotation axes.
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At room temperature, solid sodium percarbonate has the orthorhombic crystal structure, with the Cmca crystallographic space group. The structure changes to Pbca as the crystals are cooled below about −30 °C.
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Pyridine crystallizes in an orthorhombic crystal system with space group Pna21 and lattice parameters a = 1752 pm, b = 897 pm, c = 1135 pm, and 16 formula units per unit cell (measured at 153 K). For comparison, crystalline benzene is also orthorhombic, with space group Pbca, a = 729.2 pm, b = 947.1 pm, c = 674.2 pm (at 78 K), but the number of molecules per cell is only 4. This difference is partly related to the lower symmetry of the individual pyridine molecule (C2v vs D6h for benzene). A trihydrate (pyridine·3H2O) is known; it also crystallizes in an orthorhombic system in the space group Pbca, lattice parameters a = 1244 pm, b = 1783 pm, c = 679 pm and eight formula units per unit cell (measured at 223 K).
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Plancheite is a chain silicate (inosilicate), with double chains of silica tetrahedra parallel to the c crystal axis. It occurs as sprays of acicular or fibrous radial clusters, with fibers extended parallel to the chains, i.e. along the c crystal axis; it can also form tiny tabular or platy crystals. It is a member of the orthorhombic crystal class m m m (2/m 2/m 2/m), which is the most symmetrical class in the orthorhombic system.
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Empressite is a mineral form of silver telluride, AgTe. It is a rare, grey, orthorhombic mineral with which can form compact masses, rarely as bipyrimidal crystals. Recent crystallographic analysisL. Bindi et al.
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Vanadiocarpholite (Mn+2V+3AlSi2O6(OH)4) is straw yellow to brown silicate mineral. It crystallizes in the orthorhombic crystal system. It is the vanadium rich variety of carpholite (Mn+2Al2Si2O6(OH)4).
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The optical class is biaxial. Bonaccordite has an orthorhombic crystal system with a point group of 2/m 2/m 2/m. The crystals are structured as elongated prisms within another material.
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Hydroxocobalamin acetate occurs as odorless, dark-red orthorhombic crystals. The injection formulations appear as clear, dark-red solutions. It has a distribution coefficient of 1.133 × 10-5 and a pKa of 7.65.
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InBr is a red crystalline solid, mp 285 °C. It has the same structure as \beta-TlI, with an orthorhombic distorted rock salt structure. It can be prepared from indium metal and InBr3.
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Gem quality enstatite from Myanmar (size: 2.4×1.0×0.8 cm) Most natural crystals are orthorhombic (space group Pbca) although three polymorphs are known. The high temperature, low pressure polymorphs are protoenstatite and protoferrosilite (also orthorhombic, space group Pbcn) while the low temperature forms, clinoenstatite and clinoferrosilite, are monoclinic (space group P21/c). Weathered enstatite with a small amount of iron takes on a submetallic luster and a bronze-like color. This material is termed bronzite, although it is more correctly called altered enstatite.
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At higher temperatures the crystals take on cubic form, whereas at the lowest temperatures they can transform to an orthorhombic crystal group. For some types there are two more phases, and as the crystal is cooled it goes from cubic, to monoclinic, to triclinic to orthorhombic. This change to higher symmetry on cooling is very unusual in solids. For some langbeinites only the cubic form is known, but that may be because it has not been studied at low enough temperatures yet.
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Potassium picrate, or potassium 2,4,6-trinitrophenolate, is an organic chemical, a picrate of potassium. It is a reddish yellow or green crystalline material. It is a primary explosive. Anhydrous potassium picrate forms orthorhombic crystals.
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Crystals are orthorhombic with space group Pbcn, and with unit cell dimensions a=10.66 b=12.74 c=7.47 Å, and unit cell volume 1014 Å3. The density is 3.884. It contains rings of B3O3F63-.
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Avogadrite ((K,Cs)BF4) is a potassium-caesium tetrafluoroborate in the halide class. Avogadrite crystallizes in the orthorhombic system (space group Pnma) with cell parameters a 8.66 Å, b 5.48 Å and c Å 7.03.
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Ixiolite was originally reported as crystallizing in the monoclinic crystal system. Detailed studies of the scandium, tin and titanium rich varieties indicate that they form crystals in the orthorhombic system whereas tungsten ixiolite is monoclinic.
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Sc4.5–xB57–y+zC3.5–z (x = 0.27, y = 1.1, z = 0.2) has an orthorhombic crystal structure with space group Pbam (No. 55) and lattice constants of a = 1.73040(6), b = 1.60738(6) and c = 1.44829(6) nm. This phase is indicated as ScB12.5C0.8 (phase IV) in the phase diagram of figure 17. This rare orthorhombic structure has 78 atomic positions in the unit cell: seven partially occupied Sc sites, four C sites, 66 B sites including three partially occupied sites and one B/C mixed- occupancy site.
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Russellite is a bismuth tungstate mineral with the chemical formula Bi2WO6.Russellite: Russellite data on Mindat.org It crystallizes in the orthorhombic crystal system. Russellite is yellow or yellow-green in color, with a Mohs hardness of .
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Carpholite is a manganese silicate mineral with formula Mn2+Al2Si2O6(OH)4. It occurs as yellow clusters of slender prisms or needles. It crystallizes in the orthorhombic system. The carpholite group includes ferrocarpholite, magnesiocarpholite, vanadiocarpholite, and potassiccarpholite.
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It melts to a light yellow liquid 95.3 °C and boils at 444.6 °C. Sulfur has an abundance on earth one-tenth that of oxygen. It has an orthorhombic polyatomic (CN 2) crystalline structure, and is brittle.
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Kainosite, is part of the orthorhombic crystal class minerals, which is a system that results from stretching a cubic lattice along two of its orthogonal pairs. Kainosite is a biaxial mineral, so the light entering its crystals will be polarized in two vibration directions (XYZ) for it has two optic axes. Because Kainosite is orthorhombic, the vibration directions XYZ coincide with the a,b,c crystallography axes. Kainosite is very rare and mostly found in Russia in vugs, pegmatites, granites, and alkalic complex as an altered product of the mineral kuliokite.
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Hafnia typically adopts the same structure as zirconia (ZrO2). Unlike TiO2, which features six-coordinate Ti in all phases, zirconia and hafnia consist of seven-coordinate metal centres. A variety of other crystalline phases have been experimentally observed, including cubic fluorite (Fmm), tetragonal (P42/nmc), monoclinic (P21/c) and orthorhombic (Pbca and Pnma).Table III, It is also known that hafnia may adopt two other orthorhombic metastable phases (space group Pca21 and Pmn21) over a wide range of pressures and temperatures, presumably being the sources of the ferroelectricity observed in thin films of hafnia.
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Gismondine is a mineral with the chemical formula CaAl2Si2O8·4(H2O). It is a zeolite or hydrated alumino-silicate. It forms colorless, bipyramidal crystals of orthorhombic symmetry. Gismondine was named for Italian mineralogist Carlo Giuseppe Gismondi (1762–1824).
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Ferrimolybdite is a hydrous iron molybdate mineral with formula: Fe3+2(MoO4)3·8(H2O) or Fe3+2(MoO4)3·n(H2O). It forms coatings and radial aggregates of soft yellow needles which crystallize in the orthorhombic system.
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DPPH has several crystalline forms which differ by the lattice symmetry and melting point (m.p.). The commercial powder is a mixture of phases which melts at ~130 °C. DPPH-I (m.p. 106 °C) is orthorhombic, DPPH-II (m.p.
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Orthorhombic Fe3C. Iron atoms are blue. The iron-carbon phase diagram In the iron–carbon system (i.e. plain-carbon steels and cast irons) it is a common constituent because ferrite can contain at most 0.02wt% of uncombined carbon.
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The crystal system of thomsonite is orthorhombic. The Mohs hardness is 5 to 5.5. It is transparent to translucent and has a density of 2.3 to 2.4. It may be colorless, white, beige, or somewhat green, yellow, or red.
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It is believed that the phase transition between the hexagonal (ice Ih) and orthorhombic (ice XI) phases of ice is enabled by proton tunneling. The occurrence of correlated proton tunneling in clusters of ice has also been reported recently.
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Meryrowitzites spectrum is similar to that of Zellerites. However, Meyrowitzite's spectrum has a larger number of bands primarily in the UO2+2. This is most likely due to the site- symmetry which for Meyrowitzite is monoclinic and orthorhombic for Zellerite.
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Iron disilicide (FeSi2) is an intermetallic compound, a silicide of iron that occurs in nature as the rare mineral linzhiite. At room temperature it forms orthorhombic crystals (β phase), which convert into a tetragonal α phase upon heating to 970 °C.
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Gwihabaite is a rare ammonium potassium nitrate mineral (NH4,K)(NO3). It is orthorhombic in form, colorless with a vitreous luster. It has a Mohs hardness of 5 and a specific gravity of 1.77. It is deliquescent and water-soluble.
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Photomicrographs of a thin section containing an amphibole crystal. In cross-polarized light on left, plane-polarized light on right. Amphiboles crystallize into two crystal systems, monoclinic and orthorhombic. In chemical composition and general characteristics they are similar to the pyroxenes.
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Oosterboschite is a rare selenide mineral with the formula (Pd,Cu)7Se5. It crystallises in the orthorhombic crystal system. It has a creamy yellow colour and a Moh's hardness of 5. It is often found as grains with no clear shape.
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Sokolova, E., Hawthorne, F.C. (2008) From Structure Topology to Chemical Composition. IV. Titanium Silicates: The Orthorhombic Polytype of Nabalamprophyllite from the Lovozero Massif, Kola Peninsula, Russia. The Canadian Mineralogist, 46, 1323-1331. This mineral belongs to the space group Pnmn.
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Its symmetry is either hexagonal (space group P63mc) or orthorhombic (Cmcm) depending on the phase. There, close-packed Re layers alternate with puckered triangular boron layers along the (001) plane. This can be seen above on the example of osmium diboride.
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Crystal structure of hexagonal (α or 2H) MoTe2 Crystal structure of orthorhombic (β', 1T' or Td) and monoclinic (β or 1T, shadow) MoTe2 Electron micrograph of monoclinic 1T' MoTe2 taken along the [100] crystal axis MoTe2 commonly exists in three crystalline forms with rather similar layered structures: hexagonal α (2H-MoTe2), monoclinic β (1T'-MoTe2) and orthorhombic β'. At room temperature it crystallises in the hexagonal system similar to molybdenum disulfide. Crystals are platy or flat. MoTe2 has unit cell sizes of a=3.519 Å c=13.964 Å and a specific gravity of 7.78 g·cm−3.
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Bursaite's structure has not been well studied, and only basic structural information is known. Bursaite is an orthorhombic, dipyramidal mineral. Its symmetry is 2/m2/m2/m, space group Bbmm.Anthony, J.W., Bideaux, R., Bladh, K., Nichols, M. Bursaite. (2003) Mineral Data Publishing.
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In two dimensions there are two orthorhombic Bravais lattices: primitive rectangular and centered rectangular. The primitive rectangular lattice can also be described by a centered rhombic unit cell, while the centered rectangular lattice can also be described by a primitive rhombic unit cell.
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Tantalite is also very close to tapiolite. Those minerals have same chemical composition, but different crystal symmetry orthorhombic for tantalite and tetragonal for tapiolite. Tantalite is black to brown in both color and streak. Manganese- rich tantalites can be brown and translucent.
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Pentamethylantimony is colourless. At -143°V it crystallizes in the orthorhombic system with space group Ccmm. Unit cell dimensions are a=6.630 Å b=11.004 Å c=11.090 Å. There are four formula per unit cell. Unit cell volume is 809.1 Å3.
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Vulcanite is a rare copper telluride mineral. The mineral has a metallic luster, and has a green or bronze-yellow tint. It has a hardness between 1 and 2 on the Mohs scale (between talc and gypsum). Its crystal structure is orthorhombic.
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Polarite (Pd,(Bi,Pb)), is an opaque, yellow-white mineral. Its crystals are orthorhombic pyramidal, but can only be seen through a microscope. It has a metallic luster and leaves a white streak. Polarite is rated 3.5 to 4 on the Mohs Scale.
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Enargite is a copper arsenic sulfosalt mineral with formula Cu3AsS4. It takes its name from the Greek word , "distinct". Enargite is a steel gray, blackish gray, to violet black mineral with metallic luster. It forms slender orthorhombic prisms as well as massive aggregates.
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Majority of crystals show zonation (Fe increasing from core to rim). It common twinned on {110} and {310}, simulating hexagonal symmetry. Sekaninaite is classified under the space group Cccm; it is an orthorhombic crystal that is found in series with cordierite (Stanek, 1975).
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Calumetite occurs as a brilliant azure to powder blue mineral. It has a hardness of 2 with good cleavage along the {001} direction and belongs to the orthorhombic crystal system. Calumetite has a bluish-white streak. Its luster is pearly on cleavage.
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Bursaite is a sulfosalt of the lillianite family. It has the formula Pb5Bi4S11 and orthorhombic structure. Bursaite is named after Bursa Province, Turkey, where it was discovered.Rasit, T. (1954-55) A study on the concentration tests and beneficiation of the Uludag tungsten ore . Bull.
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Lyonsite (Cu3Fe+34(VO4)6) is a rare black vanadate mineral that is opaque with a metallic lustre. It crystallizes in the orthorhombic crystal system. Lyonsite often occurs as small tabular typically well formed crystals. Lyonsite has a good cleavage and a dark gray streak.
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The elements studied to date as solid samples have eight kinds of crystal structures: cubic, body-centered cubic, face-centered cubic, hexagonal, monoclinic, orthorhombic, rhombohedral, and tetragonal. For some of the synthetically produced transuranic elements, available samples have been too small to determine crystal structures.
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American Mineralogist, 89, 15-19. The specific geologic setting within its origin is the Carleton talc quarry in Chester, Vermont. Chesterite has an orthorhombic crystal structure, which means it has three crystallographic axes of unequal length. All of the axes are perpendicular to each other.
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It crystallizes in the orthorhombic system. The locality at Håkansboda, Sweden has rare twinned dipyramidal crystals (see photo). It is brittle with a Mohs hardness of 5 and a specific gravity of 5.95. It occurs in high temperature hydrothermal deposits with pyrrhotite and chalcopyrite.
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Whiteite is invariably twinned, giving the crystals a pseudo-orthorhombic appearance, and the cleavage is good to perfect. Whiteite is quite soft, with hardness 3 to 4, between calcite and fluorite. Its specific gravity is 2.58, similar to that of quartz. Whiteite is not radioactive.
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Hashemite is orthorhombic, with space group Pnma. I was found together with chromium- bearing ettringite and an apatite group mineral in the Hatrurim Formation, known for the occurrence of rocks formed due to natural pyrometamorphism. Hashemite is named after the Hashemite Kingdom of Jordan.
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Hambergite (Be2BO3OH) is a beryllium borate mineral named after Swedish explorer and mineralogist Axel Hamberg (1863–1933). The mineral occurs as white or colorless orthorhombic crystals. Tabular, terminated crystal from the Gem Hill, Mesa Grande District, San Diego County, California (size: 1.5 x .8 x .
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Similar to yttrium, rare-earth metals from Gd to Lu can form REB41Si1.2-type boride. The first such compound was synthesized by solid-state reaction and its structure was deduced as YB50. X-ray powder diffraction (XRD) and electron diffraction indicated that YB50 has an orthorhombic structure with lattice constants a = 1.66251(9), b = 1.76198 and c = 0.94797(3) nm. The space group was assigned as P21212. Because of the close similarity in lattice constants and space group, one might expect that YB50 has the γ-AlB12-type orthorhombic structure whose lattice constants and space group are a = 1.6573(4), b = 1.7510(3) and c = 1.0144(1) nm and P21212.
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Nadorite is a mineral with the chemical formula PbSbO2Cl. It crystallizes in the orthorhombic crystal system and is brown, brownish-yellow or yellow in color, with a white or yellowish-white streak. Nadorite is named after Djebel Nador in Algeria, where it was first identified in 1870.
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It forms orthorhombic crystals. Blossite was also first described for specimens from the Izalco volcano. Ziesite and blossite are polymorphs, different crystal structure for the same chemical composition and are quite similar in physical properties. Associated minerals include stoiberite, shcherbinaite, bannermanite, fingerite, mcbirneyite, blossite, chalcocyanite and chalcanthite.
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Neptunium hexafluoride forms orange orthorhombic crystals that melt at 54.4 °C and boil at 55.18 °C under standard pressure. The triple point is 55.10 °C and 1010 hPa (758 Torr).Keller C. (1969) Die Chemie des Neptuniums. In: Anorganische Chemie. Fortschritte der Chemischen Forschung, vol 13/1.
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Spertiniite is a rare copper hydroxide mineral. Chemically it is copper(II) hydroxide with formula Cu(OH)2. It occurs as blue to blue green tabular orthorhombic crystal aggregates in a secondary alkaline environment altering chalcosite. Associated minerals include chalcocite, atacamite, native copper, diopside, grossular and vesuvianite.
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Calcium titanate is obtained as orthorhombic crystals, more specifically perovskite structure. In this motif, the Ti(IV) centers are octahedral and the Ca2+ centers occupy a cage of 12 oxygen centres. Many useful materials adopt related structures, e.g. barium titanate or variations of the structure, e.g.
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Metaborates are derivatives of BO2−. Like metaboric acid, the metaborates exist with disparate structures. Examples are sodium and potassium metaborates, salts formed by deprotonation of orthorhombic metaboric acid containing the cyclic B3O63− ion and calcium metaborate, Ca(BO2)2, which contains the chain polymeric ion (BO2−)n.
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Compounds of nickel with other metals can be called alloys. The substances with fixed composition include nickel aluminide (NiAl) melting at 1638° with hexagonal structure. NiY, NiY3, Ni3Y, Ni4Y, NiGd3, BaNi2Ge2 changes structure from orthorhombic to tetragonal around 480 °C. This is a ternary intermetallic compound.
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Witherite is a barium carbonate mineral, BaCO3, in the aragonite group. Witherite crystallizes in the orthorhombic system and virtually always is twinned. The mineral is colorless, milky-white, grey, pale-yellow, green, to pale-brown. The specific gravity is 4.3, which is high for a translucent mineral.
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Carbides are predicted to be more likely lower in the mantle as experiments have shown a much lower oxygen fugacity for high pressure iron silicates. Cohenite remains stable to over 187 GPa, but is predicted to have a denser orthorhombic Cmcm form in the inner core.
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BaCl2 crystallizes in two forms (polymorphs). One form has the cubic fluorite (CaF2) structure and the other the orthorhombic cotunnite (PbCl2) structure. Both polymorphs accommodate the preference of the large Ba2+ ion for coordination numbers greater than six.Wells, A. F. (1984) Structural Inorganic Chemistry, Oxford: Clarendon Press. .
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Edingtonite is a white, gray, brown, colorless, pink or yellow zeolite mineral. Its chemical formula is BaAl2Si3O10·4H2O. It has varieties with tetragonal, orthorhombic or triclinic crystals.Richard V. Gaines, H. Catherine W. Skinner, Eugene E. Foord, Brian Mason, and Abraham Rosenzweig: "Dana's new mineralogy", pp. 1683-1684.
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Trigonal, tetragonal and hexagonal crystals have a single optic axis, parallel to the c crystal axis. They are said to be uniaxial. Triclinic, monoclinic and orthorhombic crystals have two optic axes, and are said to be biaxial. The angle between the two axes is denoted by 2V.
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Ammonium sulfate becomes ferroelectric at temperatures below -49.5 °C. At room temperature it crystallises in the orthorhombic system, with cell sizes of a = 7.729 Å, b = 10.560 Å, c = 5.951 Å. When chilled into the ferrorelectric state, the symmetry of the crystal changes to space group Pna21.
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Wyartite ·7H2O is a uranium bearing mineral named after Jean Wyart (1902–1992), mineralogist at the Sorbonne, Paris. It has greenish-black, black, or violet-black, translucent to opaque orthorhombic crystals. A hardness of 3 - 4 Mohs. Its other names are Ianthinite (of Bignand), Wyartit and Wyartita.
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Caledonite, whose name derives from Caledonia, the historical name of its place of discovery (Scotland), is a richly colored blue-green sulfate- carbonate mineral of lead and copper with an orthorhombic crystal structure. It is an uncommon mineral found in the oxidized zones of copper-lead deposits.
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Cesbronite is a copper-tellurium oxysalt mineral with the chemical formula Cu3Te6+O4(OH)4 (IMA 17-C). It is colored green and its crystals are orthorhombic dipyramidal. Cesbronite is rated 3 on the Mohs Scale.Webmineral entry It is named after Fabien Cesbron (born 1938), a French mineralogist.
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Naphthanthrone is an organic carbon based molecule formed of five rings, of which four are benzene rings, joined in the shape of the Olympic rings. The compound can be synthesized by the condensation of pyrene and glycerol in sulfuric acid. Its crystals belong to the orthorhombic crystal system.
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Calcium formate is the calcium salt of formic acid. It is also known as E238. Under this E number it is used as an animal feed preservative within EU, but not in foods intended for people. Calcium formate is stable at room temperature, is inflammable and forms orthorhombic crystals.
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YB50 crystals have orthorhombic structure with space group P21212 (No. 18), a = 1.66251 nm, b = 1.76198 nm, c = 0.94797 nm. They can be grown by heating a compressed pellet of yttria (Y2O3) and boron powder to ~1700 0C. Above this temperature YB50 decomposes into YB12 and YB66 without melting.
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The most common form of FePO4 adopts the structure of α-quartz. As such the P and Fe have tetrahedral molecular geometry. At high pressures, a phase change occurs to a more dense structure with octahedral Fe centres. Two orthorhombic structures and a monoclinic phase are also known.
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Lead(II) chromate is the inorganic compound with the formula (PbCrO4). It has a vivid yellow color and is insoluble in all solvents. Two polymorphs of lead chromate are known, orthorhombic and the more stable monoclinic form. Monoclinic lead chromate is used in paints under the name chrome yellow.
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Hönle, Wolfgang; Furuseth, Sigrid; von Schnering, Hans Georg "Synthesis and crystal structure of ordered, orthorhombic α-NbBr5" Zeitschrift für Naturforschung, B: Chemical Sciences 1990, vol. 45, pp. 952-6. The pentachloride and pentaiodides of Nb and Ta share this structural motif. There is no bond between the Nb centres.
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Nabesite is a rare silicate mineral of the zeolite group with the chemical formula Na2BeSi4O10·4(H2O). It occurs as colorless to white orthorhombic crystals in thin platy mica like sheets. It has the zeolite structure. Its Mohs hardness is 5 to 6 and its specific gravity is 2.16.
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Tin(II) selenide can be formed by reacting the elements tin and selenium above 350 °C. Problems with the composition are encountered during synthesis. Two phases exist—the hexagonal SnSe2 phase and the orthorhombic SnSe phase. Specific nanostructures can be synthesized, but few 2D nanostructures have been prepared.
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The crystal structure of the solid is of the orthorhombic system with space group Pbcn; number 60. The unit cell dimensions are a=13.991 Å b=11.3985 Å c 7.2081 Å. The molecules in the gas take the same form as in the solid with a C2 symmetry.
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Refractive index is inversely proportional to speed, so the refractive indices for the X, Y and Z directions increase from X to Z.Klein and Hurlbut (1993) Manual of Mineralogy 21st Edition. Wiley Carminite is orthorhombic and for an orthorhombic crystal the optical directions correspond to the crystal axes a, b and c, but not necessarily in that order. For carminite the orientation is X = c, Y = a and Z = b and the refractive indices are high, with nα = 2.070, nβ = 2.070, nγ = 2.080, only a little less than diamond at 2.4.Foshag (1937) American Mineralogist 22: 479-484 The maximum birefringence δ is the difference between the highest and lowest refractive index; for carminite δ = 0.010.
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Groutite is a manganese oxide mineral with formula Mn3+O(OH). It is a member of the diaspore group and is trimorphous with manganite and feitknechtite. It forms lustrous black crystals in the orthorhombic system. It occurs in weathered banded iron formations, metamorphosed manganese ore bodies and hydrothermal ore environments.
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Euchroite is a hydrated copper arsenate hydroxide mineral with formula: Cu2AsO4OH·3H2O. It is a vitreous green to emerald green mineral crystallizing in the orthorhombic system. It has a Mohs hardness of 3.5 - 4.0 and a specific gravity of 3.39 - 3.45. It was first described in 1823 in Ľubietová, Slovakia.
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ED.50 [no] [no] (IUPAC: tetrapotassium uranyl tricarbonate) #Agrinierite (compreignacite: IMA1971-046) 4.GB.05 #Aguilarite (acanthite: 1891) 2.BA.55 (IUPAC: tetrasilver selenide sulfide) ##Monoclinic ‘acanthite-like’ series (from Ag2S-Ag2S0.4Se0.6) ##Orthorhombic ‘naumannite-like’ series (from Ag2S0.3Se0.7-Ag2Se) #Aheylite (turquoise: IMA1984-036) 8.DD.15 #Ahlfeldite (cobaltomenite: 1935) 4.
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Thenardite crystallizes in the orthorhombic system and often forms yellowish, reddish to gray white prismatic crystals although usually in massive crust deposits. Thenardite is fluorescent, white in shortwave and yellow-green in longwave UV radiation. In humid conditions, thenardite gradually absorbs water and converts to the mineral mirabilite, Na2SO4·10H2O.
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Absorption is equal along the Y and Z optic directions, but less along the X optic direction. When a birefringent crystal is rotated between crossed polarizers it will turn dark every 90° of rotation. This effect is known as extinction. Carminite exhibits the parallel extinction that is characteristic of orthorhombic crystals.
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Sarabauite is a biaxial negative mineral. All minerals of the monoclinic, orthorhombic, and triclinic systems are biaxial minerals. Unlike uniaxial minerals, biaxial crystals have 2 optic axes. This means they have two directions in which light can travel without birefringence, three principal axes, and accordingly three different indices of refraction.
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Under pressure nitrogen can form crystalline van der Waals compounds with other molecules. It can form an orthorhombic phase with methane above 5 GPa. With helium He(N2)11 is formed. N2 crystallizes with water in nitrogen clathrate and in a mixture with oxygen O2 and water in air clathrate.
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Crystals are generally transparent to translucent. Crystals are not luminescent or fluorescent. Jerrygibbsite forms orthorhombic crystals with an imperfect cleavage along the {001} plane, which can be seen by opaque lamellae alternating with the transparent jerrygibbsite. Optically, jerrygibbsite is negative biaxial with 2V = 72˚ and a maximum birefringence of 0.017.
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Structure of cubic BaTiO3. The red spheres are oxide centres, blue are Ti4+ cations, and the green spheres are Ba2+. The solid exists in one of four polymorphs depending on temperature. From high to low temperature, these crystal symmetries of the four polymorphs are cubic, tetragonal, orthorhombic and rhombohedral crystal structure.
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Loellingite, also spelled löllingite, is an iron arsenide mineral with formula FeAs2. It is often found associated with arsenopyrite (FeAsS) from which it is hard to distinguish. Cobalt, nickel and sulfur substitute in the structure. The orthorhombic lollingite group includes the nickel iron arsenide rammelsbergite and the cobalt iron arsenide safflorite.
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Leucopyrite is an old synonym for loellingite. It forms opaque silvery white orthorhombic prismatic crystals often exhibiting crystal twinning. It also occurs in anhedral masses and tarnishes on exposure to air. It has a Mohs hardness of 5.5 to 6 and a quite high specific gravity of 7.1 to 7.5.
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This property is called pleochroism. Dyscrasite exhibits very weak reflected light pleochroism. Dyscrasite belongs to the orthorhombic crystal class, meaning all three of its axes (a, b, and c) are unequal in length and are 90° to each other.Klein, C., and Dutrow, B. (2007) The Manual of Mineral Science, 23rd ed.
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Madocite is a mineral with a general formula of Pb17(Sb,As)16S41. Madocite was named for the locality of discovery, Madoc, Ontario, Canada. It is found in the marbles of the Precambrian Grenville Limestone. It is orthorhombic (rectangular prism with a rectangular base) and in the point group mm2.
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Khinite is a rare tellurate mineral with the formula Pb2+Cu2+3TeO6(OH)2 It crystallizes in the orthorhombic system and has a bottle-green colour. It is often found as dipyramidal, curved or corroded crystals no more than 0.15 mm in size. The tetragonal dimorph of khinite is called parakhinite.
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Liebigite, like some other uranium minerals, is fluorescent under UV light and is also translucent. It crystallizes in the orthorhombic system, but only rarely forms distinct crystals. It typically forms encrustations or granular aggregates. It was first described in 1848 for an occurrence in Adrianople, Edirne Province, Marmara Region, Turkey.
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John Wiley Publishers, p.497. Nabalamprophyllite is monoclinic, which means crystallographically, it contains three axes of unequal length and the angles between two of the axes are 90°, and one is less than 90°. It belongs to the space group P2/m. The mineral also has an orthorhombic polytype (nabalamprophyllite-2O).
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Boracite is a magnesium borate mineral with formula: Mg3B7O13Cl. It occurs as blue green, colorless, gray, yellow to white crystals in the orthorhombic - pyramidal crystal system. Boracite also shows pseudo-isometric cubical and octahedral forms. These are thought to be the result of transition from an unstable high temperature isometric form on cooling.
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Danburite is a calcium boron silicate mineral with a chemical formula of CaB2(SiO4)2. It has a Mohs hardness of 7 to 7.5 and a specific gravity of 3.0. The mineral has an orthorhombic crystal form. It is usually colourless, like quartz, but can also be either pale yellow or yellowish-brown.
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Phenylboronic acid is soluble in most polar organic solvents and is poorly soluble in hexanes and carbon tetrachloride. This planar compound has idealized C2V molecular symmetry. The boron atom is sp2-hybridized and contains an empty p-orbital. The orthorhombic crystals use hydrogen bonding to form units made up of two molecules.
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Bertrandite is a beryllium sorosilicate hydroxide mineral with composition: Be4Si2O7(OH)2. Bertrandite is a colorless to pale yellow orthorhombic mineral with a hardness of 6-7. It is commonly found in beryllium rich pegmatites and is in part an alteration of beryl. Bertrandite often occurs as a pseudomorphic replacement of beryl.
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It is stable up to 640 °C. SrB5O7F3 The crystal structure is orthorhombic with space group Cmc21. The subunits are double rings B5O9F3 which are fused at a boron and oxygen atom. There is a fluorine attached to this boron, and also to the boron atoms connected to the ring bridging oxygen.
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The mineral's crystal structure was first determined in 1985 and refined in 2012. The mineral crystallizes in the orthorhombic crystal system. The structure is formed by chains of corner-sharing ZnO4 tetrahedra linked together by Si2O7 tetrahedral pairs. Calcium ions occupy vacancies and coordinate to five oxygen atoms and one water molecule.
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Tellurium atoms form a distorted octahedron around the molybdenum atoms. This high-temperature form, termed β–MoTe2 can be quenched to room temperature by rapid cooling. In this metastable state β-MoTe2 can survive below 500 °C. When metastable β–MoTe2 is cooled below −20 °C, its crystal form changes to orthorhombic.
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Vaterite is a mineral, a polymorph of calcium carbonate (CaCO3). It was named after the German mineralogist Heinrich Vater. It is also known as mu-calcium carbonate (μ-CaCO3) and has a JCPDS number of 13-192. Vaterite belongs to the hexagonal crystal system, whereas calcite is trigonal and aragonite is orthorhombic.
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Meneghinite is a sulfosalt mineral with the chemical formula CuPb13 Sb7S24.Mindat information page for Meneghinite In the orthorhombic crystal system, meneghinite has a Mohs hardness of , one perfect cleavage and a conchoidal fracture. It is a blackish lead-grey in colour and gives a black shining streak. Its lustre is metallic.
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Tungstite is a hydrous tungsten oxide mineral with formula: WO3·H2O. It is a secondary mineral formed by the weathering of other tungsten containing minerals. It crystallizes in the orthorhombic system in translucent yellow to yellow green masses. It is clay-like with Mohs hardness of 2.5 and a specific gravity of 5.5.
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The compound is prepared by the reaction of titanium dioxide with a mixture of KH2PO4 and K2HPO4 near 1300 K. The potassium salts serve both as reagents and flux. The material has been characterized by X-ray crystallography. KTP has an orthorhombic crystal structure. It features octahedral Ti(IV) and tetrahedral phosphate sites.
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Oriental topaz is composed of nearly pure alumina, silica, and fluoric acid; its shape is an orthorhombic prism with a cleavage transverse to its long axis. It is extremely hard and has a double refraction. When rubbed or heated it becomes highly electric. It varies in colour according to the country of origin.
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Under atmospheric pressure mercuric oxide has two crystalline forms: one is called montroydite (orthorhombic, 2/m 2/m 2/m, Pnma), and the second is analogous to the sulfide mineral cinnabar (hexagonal, hP6, P3221); both are characterized by Hg-O chains. At pressures above 10 GPa both structures convert to a tetragonal form.
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The room temperature form α-MgH2 has a rutile structure. There are at least four high pressure forms: γ-MgH2 with α-PbO2 structure, cubic β-MgH2 with Pa-3 space group, orthorhombic HP1 with Pbc21 space group and orthorhombic HP2 with Pnma space group. Additionally a non stoichiometric MgH(2-δ) has been characterised, but this appears to exist only for very small particles (bulk MgH2 is essentially stoichiometric, as it can only accommodate very low concentrations of H vacancies). The bonding in the rutile form is sometimes described as being partially covalent in nature rather than purely ionic; charge density determination by synchrotron x-ray diffraction indicates that the magnesium atom is fully ionised and spherical in shape and the hydride ion is elongated.
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However, later studies showed that bursaite's characteristics are nearly identical to the mineral lillianite's. Bursaite's X-ray diffraction pattern is nearly identical to that of lillianite's, with only slightly more peaks than lillianite. This was eventually explained as a mixture of two orthorhombic phases in the mineral.Jambor, J., Burke, E. (1989) New Mineral Names.
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The atomic scale structure of olivine looking along the a axis. Oxygen is shown in red, silicon in pink, and magnesium/iron in blue. A projection of the unit cell is shown by the black rectangle. The molecular structure of peridot consist of isomorphic olivine, silicate, magnesium and iron in an orthorhombic crystal system.
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Hypersthene is a common rock-forming inosilicate mineral belonging to the group of orthorhombic pyroxenes. Its chemical formula is (Mg,Fe)SiO3. It is found in igneous and some metamorphic rocks as well as in stony and iron meteorites. Many references have formally abandoned this term, preferring to categorise this mineral as enstatite or ferrosilite.
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ALH 84001 is an extraterrestrial example of an orthopyroxenite. It is an achondrite meteorite from Mars. Orthopyroxenite is an ultramafic and ultrabasic rock that is almost exclusively made from the mineral orthopyroxene, the orthorhombic version of pyroxene and a type of pyroxenite. It can have up to a few percent of olivine and clinopyroxene.
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Anglesite is a lead sulfate mineral with the chemical formula PbSO4. It occurs as an oxidation product of primary lead sulfide ore, galena. Anglesite occurs as prismatic orthorhombic crystals and earthy masses, and is isomorphous with barite and celestine. It contains 74% of lead by mass and therefore has a high specific gravity of 6.3.
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Nevadaite is a pale-green to turquoise colored mineral belonging to the phosphate group. It exhibits a radial crystal habit consisting of prismatic crystals covering areas up to 2 cm. It has a pale-blue streak, a vitreous luster, and is not fluorescent. Nevadaite is in the orthorhombic crystal system and displays conchoidal fracture.
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KMnO4 forms orthorhombic crystals with constants: a = 910.5 pm, b = 572.0 pm, c = 742.5 pm. The overall motif is similar to that for barium sulfate, with which it forms solid solutions."Handbook of Preparative Inorganic Chemistry" Brauer, E., Ed.; Academic: New York, 1963. In the solid (as in solution), each MnO4− centres are tetrahedral.
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An alternate stable form, if it exists, may appear at pressures of at least 50 GPa and temperatures of at least 1,500 K; it has been thought to have an orthorhombic or a double hcp structure. as of December 2011, recent and ongoing experiments are being conducted on high-pressure and Superdense carbon allotropes.
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Antimony triselenide is the chemical compound with the formula Sb2Se3. The material exists as the sulfosalt mineral antimonselite, which crystallizes in an orthorhombic space group.Jambor, J. L.; Grew, E. S."New Mineral Names" American Mineralogist, Volume 79, pages 387-391, 1994. In this compound, antimony has a formal oxidation state +3 and selenium −2\.
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Teallite is a sulfide mineral of tin and lead with chemical formula: PbSnS2. It occurs in hydrothermal veins and is sometimes mined as an ore of tin. Teallite forms soft silvery grey mica-like plates and crystallizes in the orthorhombic system. The Mohs hardness is 1.5 to 2 and the specific gravity is 6.4.
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Mesolite is a tectosilicate mineral with formula Na2Ca2(Al2Si3O10)3·8H2O. It is a member of the zeolite group and is closely related to natrolite which it also resembles in appearance. Mesolite crystallizes in the orthorhombic system and typically forms fibrous, acicular prismatic crystals or masses. Radiating sprays of needlelike crystals are not uncommon.
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Tin(II) selenide (SnSe) crystallizes in the orthorhombic structure that derives from a distorted rock-salt structure. It is isomorphous to germanium selenide (GeSe). The unit cell encompasses two inverted layers. Each tin atom is covalently bonded to three neighboring selenium atoms, and each selenium atom is covalently bonded to three neighboring tin atoms.
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Difluorophosphoric acid anhydride also known as phosphoryl difluoride oxide or diphosphoryl tetrafluoride (F2OPOPOF2 or P2O3F4) is an anhydride of difluorphosphoric acid. It crystallises in the orthorhombic system, with space group Pcca and Z = 4. originally in Inorg. Chem. 49 (2010) 6, 3002–3010 P2O3F4 can be made by refluxing difluorophosphoric acid with phosphorus pentoxide.
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Figure 3: Orthorhombic structure of β-La2O2MnSe2 at low temperatures. New oxyselenides of the formula Sr2AO2M2Se2 (A=Co, Mn; M=Cu, Ag) have been synthesized. They crystallize into structures consisting of alternating perovskite-like (metal oxide) and antifluorite (metal selenide) layers (Figure 2). The optical band gap of each oxyselenide is very narrow, indicating semiconductivity.
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It has an orthorhombic crystal structure. α-Sulfur is the predominant form found in "flowers of sulfur", "roll sulfur" and "milk of sulfur". It contains S8 puckered rings, alternatively called a crown shape. The S-S bond lengths are all 203.7 pm and the S-S-S angles are 107.8° with a dihedral angle of 98°.
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"Muthmann's sulfur I" or "Engel's sulfur".Steudel, 17 The most commonly encountered form of sulphur is the orthorhombic polymorph of , which adopts a puckered ring – or "crown" – structure. Two other polymorphs are known, also with nearly identical molecular structures.Greenwood, 654 In addition to S8, sulfur rings of 6, 7, 9–15, 18 and 20 atoms are known.
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AA'-graphite is an allotrope of carbon similar to graphite, but where the layers are positioned differently to each other as compared to the order in graphite. AA’ stacking of graphene planes is another crystalline form of graphite (orthorhombic, Fig. 1) which is metastable for Bernal AB graphite (hexagonal) (Fig. 2) and reveals a nanocrystalline feature.
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The crystal system is orthorhombic and is flat and tabular in appearance. It has a Mohs hardness of 3 to 4 and its cleavage is perfect. Barrerite has a white streak and a density of 2.13. It was first described in 1974 for an occurrence in Sardinia at Sant' Efisio Tower on Cape Pula in Cagliari Province.
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A section of the chain comprising edge-sharing octahedra. Oxygen atoms in back and front of the chain link to other chains to build the layer. In the gas phase, three oxygen atoms are double bonded to the central molybdenum atom. In the solid state, anhydrous MoO3 is composed of layers of distorted MoO6 octahedra in an orthorhombic crystal.
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Nyerereite is a very rare sodium calcium carbonate mineral with formula Na2Ca(CO3)2. It forms colorless, platey pseudohexagonal orthorhombic crystals that are typically twinned. It has a specific gravity of 2.54 and indices of refraction of nα=1.511, nβ=1.533 and nγ=1.535. Nyerereite is not stable in contact with the atmosphere and rapidly breaks down.
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Macphersonite, Pb4(SO4)(CO3)2 (OH)2, is a carbonate mineral that is trimorphous with leadhillite and susannite. Macphersonite is generally white, colorless, or a pale amber in color and has a white streak. It crystallizes in the orthorhombic system with a space group of Pcab. It is fairly soft mineral that has a high specific gravity.
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Schoepite, empirical formula (UO2)8O2(OH)12•12(H2O) is a rare alteration product of uraninite in hydrothermal uranium deposits. It may also form directly from ianthinite. The mineral presents as a transparent to translucent yellow, lemon yellow, brownish yellow, or amber orthorhombic tabular crystals. Although over 20 other crystal forms have been noted; rarely in microcrystalline aggregates.
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Monoclinic crystal An example of the monoclinic crystal orthoclase In crystallography, the monoclinic crystal system is one of the seven crystal systems. A crystal system is described by three vectors. In the monoclinic system, the crystal is described by vectors of unequal lengths, as in the orthorhombic system. They form a rectangular prism with a parallelogram as its base.
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Dawsonite is a mineral composed of sodium aluminium carbonate hydroxide, chemical formula NaAlCO3(OH)2. It crystallizes in the orthorhombic crystal system. It is not mined for ore. It was discovered in 1874 during the construction of the Redpath Museum in a feldspathic dike on the campus of McGill University on the Island of Montreal, Canada.
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Epsomite is a hydrous magnesium sulfate mineral with formula MgSO4·7H2O. Epsomite crystallizes in the orthorhombic system as rarely found acicular or fibrous crystals, the normal form is as massive encrustations. It is colorless to white with tints of yellow, green and pink. The Mohs hardness is 2 to 2.5 and it has a low specific gravity of 1.67.
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Kassite is a rare mineral whose chemical formula is CaTi2O4(OH)2. It crystallizes in the orthorhombic crystal system and forms radiating rosettes and pseudo-hexagonal tabular crystals which are commonly twinned. Kassite crystals are brownish pink to pale yellow in color, are translucent, and have an adamantine luster. Cleavage is distinctly visible, and the crystals are very brittle.
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Valentinite is an antimony oxide mineral with formula Sb2O3. Valentinite crystallizes in the orthorhombic system and typically forms as radiating clusters of euhedral crystals or as fibrous masses. It is colorless to white with occasional shades or tints of yellow and red. It has a Mohs hardness of 2.5 to 3 and a specific gravity of 5.76.
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Canfieldite is a rare silver tin sulfide mineral with formula: Ag8SnS6. The mineral typically contains variable amounts of germanium substitution in the tin site and tellurium in the sulfur site. There is a complete series between canfieldite and its germanium analogue, argyrodite. It forms black orthorhombic crystals which often appear to be cubic in form due to twinning.
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Tellurite is a rare oxide mineral composed of tellurium dioxide (TeO2). It occurs as prismatic to acicular transparent yellow to white orthorhombic crystals. It occurs in the oxidation zone of mineral deposits in association with native tellurium, emmonsite and other tellurium minerals. Its name comes from Tellus, which is the Latin name for the planet Earth.
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Kratochvilite is a rare organic mineral formed by combustion of coal or pyritic black shale deposits. It is a hydrocarbon with the formula of either C13H10 or (C6H4)2CH2. It is a polymorph of the aromatic hydrocarbon fluorene. It forms white, yellow to brown crystals in the orthorhombic system which occur often as a druzey encrustation.
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Lead(II) oxide, also called lead monoxide, is the inorganic compound with the molecular formula PbO. PbO occurs in two polymorphs: litharge having a tetragonal crystal structure, and massicot having an orthorhombic crystal structure. Modern applications for PbO are mostly in lead-based industrial glass and industrial ceramics, including computer components. It is an amphoteric oxide.
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Strontianite is an orthorhombic mineral, belonging to the most symmetrical class in this system, 2/m 2/m 2/m, whose general form is a rhombic dipyramid. The space group is Pmcn. There are four formula units per unit cell (Z = 4) and the unit cell parameters are a = 5.1 Å, b = 8.4 Å, c = 6.0 Å.
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Strontianite is isostructural with aragonite.Klein and Hurlbut (1993) Manual of Mineralogy 21st Edition. Wiley When the CO3 group is combined with large divalent cations with ionic radii greater than 1.0 Å, the radius ratios generally do not permit stable 6-fold coordination. For small cations the structure is rhombohedral, but for large cations it is orthorhombic.
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The mineral was named in 1863 after the forest god Tapio of Finnish mythology, and the original tapiolite material came from Sukula, Tammela, Tavastia Proper, Finland.webmineral Tapiolite Tapiolite is very close to columbite and tantalite. Those minerals have the same chemical composition, but different crystal symmetry orthorhombic for tantalite or columbite and tetragonal for tapiolite.P. Cerny et al.
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Mascagnite is a rare ammonium sulfate mineral (NH4)2SO4. It crystallizes in the orthorhombic system typically forming as stalactitic masses exhibiting good cleavage. It is soft (not higher than 2.5 on the Mohs Scale) and water- soluble. Optical properties are variable; the purest form is transparent and colorless, but opaque gray or yellow deposits are also known.
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Potassium atoms are 9-coordinated and may be viewed as distorted monocapped square prisms. At temperatures above 230 °C this converts to β-K2[TaF7], which is orthorhombic (space group: Pnma). This structure also consists of potassium ions and the complex anion [TaF7]2−. The structure of the 7-coordinate [TaF7]2− units is essentially unchanged.
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Lawsonite is a hydrous calcium aluminium sorosilicate mineral with formula CaAl2Si2O7(OH)2·H2O. Lawsonite crystallizes in the orthorhombic system in prismatic, often tabular crystals. Crystal twinning is common. It forms transparent to translucent colorless, white, and bluish to pinkish grey glassy to greasy crystals. Refractive indices are nα=1.665, nβ=1.672 - 1.676, and nγ=1.684 - 1.686.
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Chromium(III) phosphate can exist as two isomorphs. Its β-isoform is orthorhombic with the Cmcm space group (a = 0.5165, b = 0.7750, c = 0.6131 nm). The structure consists of infinite chains of trans edge-sharing CrO6 octahedra, which run parallel to the c-axis, and are linked by PO4 tetrahedra. Above 1175 °C, β-CrPO4 converts to α-CrPO4.
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Mottramite is an orthorhombic anhydrous vanadate hydroxide mineral, PbCu(VO4)(OH), at the copper end of the descloizite subgroup. It was formerly called cuprodescloizite or psittacinite (this mineral characterized in 1868 by Frederick Augustus Genth). Duhamelite is a calcium- and bismuth-bearing variety of mottramite, typically with acicular habit. Mottramite is a member of the adelite-descloizite group.
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Yttrium aluminium garnet (YAG, Y3Al5O12) is a synthetic crystalline material of the garnet group. It is a cubic yttrium aluminium oxide phase, with other examples being YAlO3 (YAP . ) in a hexagonal or an orthorhombic, perovskite- like form, and the monoclinic Y4Al2O9 (YAM ). YAG, like garnet and sapphire, has no uses as a laser medium when pure.
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Samarium(III) fluoride (SmF3) is a slightly hygroscopic solid fluoride. At room temperature, it has orthorhombic structure with space group Pnma – β-YF3 type with lattice constants a = 666,9 pm, b = 705,9 pm, c = 440,5 pm. Above 495 °C, it has the rhombohedral LaF3 structure (space group P3cl) – with lattice constants a = 707, c = 724 pm.K Rotereau et al.
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The dithionate ion represents sulfur that is oxidized relative to elemental sulfur, but not totally oxidized. Sulfur can be reduced to sulfide or totally oxidized to sulfate, with numerous intermediate oxidation states in inorganic moieties, as well as organosulfur compounds. Example inorganic ions include sulfite and thiosulfate. Sodium dithionate crystallize as orthorhombic crystals of the dihydrate ().
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Stibnite, sometimes called antimonite, is a sulfide mineral with the formula Sb2S3. This soft grey material crystallizes in an orthorhombic space group. It is the most important source for the metalloid antimony.Sabina C. Grund, K. Hanusch, H. J. Breunig, H. U. Wolf, "Antimony and Antimony Compounds" in Ullmann’s Encyclopedia of Industrial Chemistry 2006, Wiley-VCH, Weinheim.
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TcF6 is octahedral, as shown by infrared and Raman spectra. Its low-temperature orthorhombic form converts to the higher symmetry body-centred cubic form at room temperature, like other metal hexafluorides such as RhF6 and OsF6. Preliminary measurements of magnetic moment yield a value of 0.45 µB, which is lower than expected for a d1 octahedral compound.
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The chemical composition of ammolite is variable, and aside from aragonite may include calcite, silica, pyrite, or other minerals. The shell itself may contain a number of trace elements, including: aluminium; barium; chromium; copper; iron; magnesium; manganese; strontium; titanium; and vanadium. Its crystallography is orthorhombic. Its hardness is 3.5–4.5, and its specific gravity is 2.60–2.85.
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It is isometric,Bonazzi, P., Chelazzi, L., and Bindi, L., 2013. Superstructure, crystal chemistry, and cation distribution in filipstadite, a Sb5+-bearing, spinel-related mineral. American Mineralogist 98, 361-366 although it was previously though to be orthorhombic. When compared to a typical spinel, both the octahedral and tetrahedral sites are split due to cation ordering.
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Kremersite is a rare mineral which is a hydrated multiple chloride of iron, ammonium and potassium with the formula: (NH4,K)2FeCl5·H2O. Kremersite is a brown-red to orange mineral that crystallizes in the orthorhombic system. It is a water-soluble mineral that is found around volcanic fumaroles. Occurs at Vesuvius, Italy and Mt. Etna, Sicily.
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Phosphoryl bromide forms colorless crystals or thin plates with a faint orange tint. Its crystals belong to the orthorhombic space group Pnma, with intermolecular Br–O bridges creating infinite chains within the structure. The intermolecular bonding causes distortions from the C3v symmetry found in the free molecule. It reacts violently with water, forming phosphoric acid and hydrobromic acid.
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Teineite is a tellurite mineral with the formula Cu(TeO3) . 2 H2O. It has a Moh's hardness of 2.5 and it comes in many different shades of blue, ranging from cerulean blue to bluish-gray. The mineral millsite has the same chemical composition, but crystallizes in the monoclinic system, while teineite crystallizes in the orthorhombic system.
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Manganite is a mineral composed of manganese oxide-hydroxide, MnO(OH), crystallizing in the monoclinic system (pseudo-orthorhombic). Crystals of manganite are prismatic and deeply striated parallel to their length; they are often grouped together in bundles. The color is dark steel-grey to iron-black, and the luster brilliant and submetallic. The streak is dark reddish brown.
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Dumortierite is a fibrous variably colored aluminium boro-silicate mineral, Al7BO3(SiO4)3O3. Dumortierite crystallizes in the orthorhombic system typically forming fibrous aggregates of slender prismatic crystals. The crystals are vitreous and vary in color from brown, blue, and green to more rare violet and pink. Substitution of iron and other tri-valent elements for aluminium result in the color variations.
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Holmquistite is a lithium magnesium aluminium inosilicate mineral with chemical formula: Li2(Mg,Fe2+)3Al2Si8O22(OH)2. It crystallizes in the orthorhombic crystal system as prismatic crystals up to or as massive aggregates. It has a Mohs hardness of 5-6 and a specific gravity of 2.95 to 3.13. Color could vary from black, dark violet to light sky blue.
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Potassium nitrate has an orthorhombic crystal structure at room temperature, which transforms to a trigonal system at . Potassium nitrate is moderately soluble in water, but its solubility increases with temperature. The aqueous solution is almost neutral, exhibiting pH 6.2 at for a 10% solution of commercial powder. It is not very hygroscopic, absorbing about 0.03% water in 80% relative humidity over 50 days.
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In ferberite, the percentage of WO3 is around 76.3% whereas in hübnerite it is around 76.6%. In naturally occurring minerals the percent range falls within 20-80 percent. In the past it was thought that the wolframite structure possesses orthorhombic symmetry but in fact it possesses monoclinic symmetry. Short prismatic, flattened or wedge-shaped crystals are the common morphologies of wolframite crystals.
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Figure 1: The atomic scale structure of olivine looking along the a axis. Oxygen is shown in red, silicon in pink, and magnesium/iron in blue. A projection of the unit cell is shown by the black rectangle. Minerals in the olivine group crystallize in the orthorhombic system (space group Pbnm) with isolated silicate tetrahedra, meaning that olivine is a nesosilicate.
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Even though Wakabayashilite possesses the hexagonal pseudosymmetry, it actually belongs to the orthorhombic crystal system meaning it contains three axes of different length but are mutually perpendicular to one another.Klein, C., and Dutrow, B. (2007) The 23rd edition of the Manual of Mineral Science, 130. John Wiley and Sons, Inc. Hoboken, New Jersey, U.S.A. It also belongs to the space group Pna21.
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Carnallite (also carnalite) is an evaporite mineral, a hydrated potassium magnesium chloride with formula KMgCl3·6(H2O). It is variably colored yellow to white, reddish, and sometimes colorless or blue. It is usually massive to fibrous with rare pseudohexagonal orthorhombic crystals. The mineral is deliquescent (absorbs moisture from the surrounding air) and specimens must be stored in an airtight container.
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Three osmium borides are known: OsB, Os2B3 and OsB2. The first two have hexagonal structure, similar to that of rhenium diboride. Osmium diboride was first also sought as hexagonal, but one of its phase's was later reassigned to orthorhombic. In recent methods of synthesis, it has also been found that a hexagonal phase of OsB2 exists with a similar structure to ReB2.
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Common salt has a 1:1 molar ratio of sodium and chlorine. In 2013, compounds of sodium and chloride of different stoichiometries have been discovered; five new compounds were predicted (e.g., Na3Cl, Na2Cl, Na3Cl2, NaCl3, and NaCl7). The existence of some of them has been experimentally confirmed at high pressures: cubic and orthorhombic NaCl3 and two-dimensional metallic tetragonal Na3Cl.
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Nenadkevichite is a rare silicate mineral containing niobium with formula: (Na,Ca)(Nb,Ti)Si2O7·2H2O. It forms brown to yellow to rose colored orthorhombic dipyramidal crystals with a dull to earthy luster. It has a Mohs hardness of 5 and a specific gravity of 2.86. It was first reported in 1955 from a nepheline syenite pegmatite in the Kola Peninsula.
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Academic Press, Ltd.: London. The crystallographic unit cell of ZSM-5 has 96 T sites (Si or Al), 192 O sites, and a number of compensating cations depending on the Si/Al ratio, which ranges from 12 to infinity. The structure is orthorhombic (space group Pnma) at high temperatures, but a phase transition to the monoclinic space group P21/n.
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Raphides in Epipremnum Devil's ivy (600x magnification) Raphides (pronounced răfədēz, singular raphide (rāfĭd) or raphis) are needle-shaped crystals of calcium oxalate monohydrate (prismatic monoclinic crystals) or calcium carbonate as aragonite (dipyramidal orthorhombic crystals), found in more than 200 families of plants. Both ends are needle-like, but raphides tend to be blunt at one end and sharp at the other.
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Aikinite is a sulfide mineral of lead, copper and bismuth with formula PbCuBiS3. It forms black to grey or reddish brown acicular orthorhombic crystals with a Mohs hardness of 2 to 2.5 and a specific gravity of 6.1 to 6.8. It was originally found in 1843 in the Beryozovskoye deposit, Ural Mountains. It is named after Arthur Aikin (1773–1854), an English geologist.
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Lanthanum manganite is an inorganic compound with the formula LaMnO3, often abbreviated as LMO. Lanthanum manganite is formed in the perovskite structure, consisting of oxygen octahedra with a central Mn atom. The cubic perovskite structure is distorted into an orthorhombic structure by a strong Jahn–Teller distortion of the oxygen octahedra. LaMnO3 often has lanthanum vacancies as evidenced by neutron scattering.
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The mineral also has an orthorhombic polytype. In terms of its optical properties, vladimirite is anisotropic which means the velocity of light varies depending on direction through the mineral. Relief is a diagnostic characteristic of a mineral in plane polarized light that refers to the various ways different minerals "stand out". Vladimirite's calculated relief is 1.65-1.661, which is moderate.
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Due to having octahedral symmetry, armalcolite has solid solution (cation substitution) between multiple elements Fe2+, Fe3+, Mg, Al, and Ti; this is because of their similarities in atomic radii and charge. The crystallographic structure exhibited by armalcolite is an orthombic- dipyramid, thus falls in the orthorhombic category and has a 2/m 2/m 2/m point group and space group of Bbmm.
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It is quite soft with a Mohs hardness of 2.5 and a relatively high specific gravity of 6.26 to 6.55. It was discovered in 1832 in the Susannah Mine, Leadhills in the county of Lanarkshire, Scotland. It is trimorphous with susannite and macphersonite (these three minerals have the same formula, but different structures). Leadhillite is monoclinic, susannite is trigonal and macphersonite is orthorhombic.
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Compounds that were historically given the formulae REAlB14 and REB25 have the MgAlB14 structure with an orthorhombic symmetry and space group Imma (No. 74). In this structure, rare-earth atoms enter the Mg site. Aluminium sites are empty for REB25. Both metal sites of REAlB14 structure have partial occupancies of about 60–70%, which shows that the compounds are actually non- stoichiometric.
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The rare mineral adelite, is a calcium, magnesium, arsenate with chemical formula CaMgAsO4OH. It forms a solid solution series with the vanadium-bearing mineral gottlobite. Various transition metals substitute for magnesium and lead replaces calcium leading to a variety of similar minerals in the adelite - duftite group. Adelite forms variably colored (blue, green, yellow and grey) crystals in the orthorhombic crystal system.
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Naldrettite is economically important because of its chemical composition (Pd2Sb). The sample in which the new mineral was discovered had high platinum group elements (PGEs) with palladium enrichment. Naldrettite occurs as anhedral grains that are commonly attached to sulfide minerals and are associated with clinochlore. It belongs to the orthorhombic crystal system and is a part of the pyramidal class.
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Vantasselite is a rare aluminium phosphate mineral with formula: Al4(PO4)3(OH)3 •9H2O. It crystallizes in the orthorhombic system and has a white color, a hardness of 2 to 2.5, a white streak and a pearly luster. It occurs in a quartzite quarry north of Bihain, Belgium It was first described in 1987 and named after Belgian mineralogist René Van Tassel.
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Libethenite is a rare copper phosphate hydroxide mineral. It forms striking, dark green orthorhombic crystals. It was discovered in 1823 in Ľubietová, Slovakia and is named after the German name of that locality (Libethen). Libethenite has also been found in the Miguel Vacas Mine, Conceição, Vila Viçosa, Évora District, Portugal, and in Tier des Carrières, Cahai, Vielsaim, Stavelot Massif, Luxembourg Province, Belgium.
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Seeligerite is a rare complex lead chlorate iodate mineral with formula: Pb3Cl3(IO3)O. It is a yellow mineral crystallizing in the orthorhombic system. It has perfect to good cleavage in two directions and a quite high specific gravity of 6.83 due to the lead content. It is translucent to transparent with refractive indices of nα=2.120 nβ=2.320 nγ=2.320.
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Cementite (or iron carbide) is a compound of iron and carbon, more precisely an intermediate transition metal carbide with the formula Fe3C. By weight, it is 6.67% carbon and 93.3% iron. It has an orthorhombic crystal structure. It is a hard, brittle material, normally classified as a ceramic in its pure form, and is a frequently found and important constituent in ferrous metallurgy.
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Bismutite or bismuthite is a bismuth carbonate mineral with formula Bi2(CO3)O2 (bismuth subcarbonate). Bismutite occurs as an oxidation product of other bismuth minerals such as bismuthinite and native bismuth in hydrothermal veins and pegmatites.Mindat It crystallizes in the orthorhombic system and typically occurs as earthy to fibrous masses.Webmineral It was first described in 1841 for an occurrence in Saxony.
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Californium(III) fluoride (CfF3) is a yellow-green solid with a crystal symmetry that gradually changes from orthorhombic to trigonal when heated above room temperature. Californium(IV) fluoride (CfF4) is a bright green solid with a monoclinic crystal structure. Californium(II) iodide (CfI2) is a deep purple solid with a stable rhombohedral structure at room temperature and an unstable hexagonal structure.
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The Natural History Museum, London, UK. The orthorhombic system is described as having three crystallographic axes of unequal lengths, normally referred to as c (the longest axes), b (the second longest axes), and a (the smallest axes). These axes all have corresponding angles of 90 degrees.Klein, Cornelis and Dutrow, Barbara. (2007) The Manual of Mineral Science (Twenty-third edition) 187-188 p.
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Rutherfordine is a mineral containing almost pure uranyl carbonate (UO2CO3). It crystallizes in the orthorhombic system in translucent lathlike, elongated, commonly radiating in fibrous, and in pulverulent, earthy to very fine-grained dense masses. It has a specific gravity of 5.7 and exhibits two directions of cleavage. It appears as brownish, brownish yellow, white, light brown orange, or light yellow fluorescent encrustations.
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H red:O green:B violet:Mn center of yellow tetrahedrons:P Seamanite is formed of acicular crystals elongated along [001] and showing the faces {110} and {111} up to one centimeter. It has an orthorhombic crystal system and the Pbnm space group. The parameters of its unit cell are: a=7.811 Å, b=15.114 Å, c=6.691 Å, Z=4 units per unit cell.
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Bergenite forms as a dark yellow crust with well-developed, small thin needle-like crystals.Korzeb, S., Foord, E., and Lichte F. (1997), "The chemical evolution and paragenesis of uranium minerals from the Ruggles and Palermo granitic pegmatites, New Hampshire", Canadian Mineralogist 35: 135–144. An original description of bergenite is the orthorhombic symmetry and a density greater than 4.1 g/cm3.
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Tyrolite is a hydrated calcium copper arsenate carbonate mineral with formula: CaCu5(AsO4)2CO3(OH)4·6H2O. Tyrolite forms glassy blue to green orthorhombic radial crystals and botryoidal masses. It has a Mohs hardness of 1.5 to 2 and a specific gravity of 3.1 to 3.2. It is translucent with refractive indices of nα=1.694 nβ=1.726 and nγ=1.730.
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The crystal structure of tungsten trioxide is temperature dependent. It is tetragonal at temperatures above 740 °C, orthorhombic from 330 to 740 °C, monoclinic from 17 to 330 °C, triclinic from -50 to 17 °C, and monoclinic again at temperatures below -50 °C.H. A. Wriedt: The O-W (oxygen- tungsten) system. In: Bulletin of Alloy Phase Diagrams. 10, 1989, S. 368, .
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Most bonds to iodine are weaker than the analogous bonds to the lighter halogens. Gaseous iodine is composed of I2 molecules with an I–I bond length of 266.6 pm. The I–I bond is one of the longest single bonds known. It is even longer (271.5 pm) in solid orthorhombic crystalline iodine, which has the same crystal structure as chlorine and bromine.
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Larger crystals most commonly have the form of a square prism terminated by a low pyramid, the prism angle being nearly a right angle. The crystals are tetragonal in appearance, though actually orthorhombic. There are perfect cleavages parallel to the faces of the prism. The mineral also often occurs in compact fibrous aggregates, the fibers having a divergent or radial arrangement.
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Crystal structure of ice XI (c-axis in the vertical direction) Ice XI has an orthorhombic structure with space group Cmc21 containing eight molecules per unit cell. Its lattice parameters are a=4.465(3) Å, b=7.859(4) Å, and c=7.292(2) Å at 5 K. There are actually 16 crystallographically inequivalent hydrogen-ordered configurations of ice with an orthorhombic structure of eight atoms per unit cell, but electronic structure calculations show Cmc21 to be the most stable. Another possible configuration, with space group Pna21 is also of interest, as it is an antiferroelectric crystal, which Davidson and Morokuma incorrectly suggested as the most stable structure in 1984. In practice, ice XI is most easily prepared from a dilute (10 mM) KOH solution kept just below 72 K for about a week (for D2O a temperature just below 76 K will suffice).
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The name lithiophilite is derived from the Greek philos (φιλός) "friend," as lithiophilite is usually found with lithium. Lithiophylite is a resinous reddish to yellowish brown mineral crystallizing in the orthorhombic system often as slender prisms. It is usually associated with lepidolite, beryl, quartz, albite, amblygonite, and spodumene of pegmatitic origin. It rather readily weathers to a variety of secondary manganese phosphates and oxides.
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Triphylite is a lithium iron(II) phosphate mineral with the chemical formula LiFePO4.IMA-CNMNC List of Mineral Names (May 2015), International Mineralogical Association It is a member of the triphylite group and forms a complete solid solution series with the lithium manganese(II) phosphate, lithiophilite. Triphylite crystallizes in the orthorhombic crystal system. It rarely forms prismatic crystals and is more frequently found in hypidiomorphic rock.
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Struvite (magnesium ammonium phosphate) is a phosphate mineral with formula: NH4MgPO4·6H2O. Struvite crystallizes in the orthorhombic system as white to yellowish or brownish-white pyramidal crystals or in platey mica-like forms. It is a soft mineral with Mohs hardness of 1.5 to 2 and has a low specific gravity of 1.7. It is sparingly soluble in neutral and alkaline conditions, but readily soluble in acid.
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Anhydrous sodium hypochlorite can be prepared but, like many hypochlorites, it is highly unstable and decomposes explosively on heating or friction. The decomposition is accelerated by carbon dioxide at atmospheric levels. It is a white solid with the orthorhombic crystal structure. Sodium hypochlorite can also be obtained as a crystalline pentahydrate ·5, which is not explosive and is much more stable than the anhydrous compound.
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The Vickers hardness of TaB and TaB2 films and crystals is ~30 GPa. Those materials are stable to oxidation below 700 °C and to acid corrosion. TaB2 has the same hexagonal structure as most diborides (AlB2, MgB2, etc.). The mentioned borides have the following space groups: TaB (orthorhombic, Thallium(I) iodide-type, Cmcm), Ta5B6 (Cmmm), Ta3B4 (Immm), TaB2 (hexagonal, aluminum diboride-type, P6/mmm).
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Grayite is isostructural with members of the Rhabdophane group such as brockite and rhabdrophane. While previous work has identified grayite as a pseudohexagonal orthorhombic member of the rhabdophane group along with ningyoite, more contemporary work seems to maintain a hexagonal crystal structure.[Frances G. Fisher and Robert Meyrowitz, 1961, "Brockite, a New Calcium Thorium Phosphate from the Wet Mountains, Colorado", American Mineralogist, Vol. 47, pg 1336-1335.
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Cerussite crystallizes in the orthorhombic system and is isomorphous with aragonite. Like aragonite it is very frequently twinned, the compound crystals being pseudo-hexagonal in form. Three crystals are usually twinned together on two faces of the prism, producing six-rayed stellate groups with the individual crystals intercrossing at angles of nearly 60°. Crystals are of frequent occurrence and they usually have very bright and smooth faces.
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CaB5O7F3, Formula weight =263.13 Orthorhombic Cmc21 a = 9.93 Å b = 8.40 Å c = 7.97 Å Volume= 664 Å3 Z=4 Density=2.631; The structure contains a repeating pattern of alternate tiles of double rings B5O9F3. This has 4 protruding oxygen atoms that are shared with neighbours. A large B9O9 ring encloses the calcium atom. These form sheets that are stacked on each other in the b direction.
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Na3B7O11F2 Contains a pair of boroxine rings interlinked by another ring with OBF2O. The outer pair of rings is linked with extra oxygen atoms at each end to form a ladder shaped structure. It has orthorhombic structure with space group Pnma; formula weight 717.28 a=9.2659 b= 16.3431 c= 6.6326 Å Volume 1004.40 Å3 Z= 2 Density 2.372. It is transparent from 161 to 2500 nm.
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Another phase of this oxide with orthorhombic symmetry has also been reported. The black dioxide PaO2 is obtained from the pentoxide by reducing it at 1550 °C with hydrogen. It is not readily soluble in either dilute or concentrated nitric, hydrochloric or sulfuric acids, but easily dissolves in hydrofluoric acid. The dioxide can be converted back to pentoxide by heating in oxygen-containing atmosphere to 1100 °C.
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Lautite is a rare mineral belonging to the class of sulfides and sulfosalts with the general formula CuAsS. It is orthorhombic and is known to form up to 2.3 cm long prismatic or flat crystals. It is also found as grains or masses. First identified by Friedrich August Frenzel in 1880 in the Rudolphschacht mine near Lauta in Saxony, it was named after its type locality.
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Lepidocrocite (γ-FeO(OH)), also called esmeraldite or hydrohematite, is an iron oxide-hydroxide mineral. Lepidocrocite has an orthorhombic crystal structure, a hardness of 5, specific gravity of 4, a submetallic luster and a yellow-brown streak. It is red to reddish brown and forms when iron-containing substances rust underwater. Lepidocrocite is commonly found in the weathering of primary iron minerals and in iron ore deposits.
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Amorphous powder boron Boron (likely mixed allotropes) Boron can be prepared in several crystalline and amorphous forms. Well known crystalline forms are α-rhombohedral, β-rhombohedral, and β-tetragonal. In special circumstances, boron can also be synthesized in the form of its α-tetragonal and γ-orthorhombic allotropes. Two amorphous forms, one a finely divided powder and the other a glassy solid, are also known.
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BaBr2 crystallizes in a lead chloride motif, giving white orthorhombic crystals that are deliquescent. In aqueous solution BaBr2 behaves as a simple salt. Solutions of barium bromide reacts with the sulfate salts to produce a solid precipitate of barium sulfate. :BaBr2 \+ SO42− → BaSO4 \+ 2 Br− Similar reactions occur with oxalic acid, hydrofluoric acid, and phosphoric acid, giving solid precipitates of barium oxalate, fluoride, and phosphate, respectively.
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Cerium tetranitrate pentahydrate is prepared by evaporating a solution of ceric nitrate in concentrated nitric acid. It forms orthorhombic crystals with bipyramidal shape. The common crystal face Miller index is {111}, But it can have smaller faces with Miller index {010} and {110}. The density is 2.403 g/cm3. Its optical properties are that it is biaxial with 2V of 34°, and strongly dispersive.
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One of the key feature of the unit cell of YBa2Cu3O7−x (YBCO) is the presence of two layers of CuO2. The role of the Y plane is to serve as a spacer between two CuO2 planes. In YBCO, the Cu–O chains are known to play an important role for superconductivity. Tc is maximal near 92 K when x ≈ 0.15 and the structure is orthorhombic.
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There are three different crystal structures for chromium carbide corresponding to the three different chemical compositions. Cr23C6 has a cubic crystal structure and a Vickers hardness of 976 kg/mm2. Cr7C3 has a hexagonal crystal structure and a microhardness of 1336 kg/mm2. Cr3C2 is the most durable of the three compositions, and has an orthorhombic crystal structure with a microhardness of 2280 kg/mm2.
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Marthozite is an orthorhombic mineral that has a general formula of Cu(UO2)3(SeO3)3(OH)2·7H2O. It was named after Belgian mineralogist Aimé Marthoz (1894-1962), former Director-general of the Union Minière du Haut Katanga - UMHK. It is usually found in cavities in selenian (selenium- containing) digenite. It is specifically found in the zones of oxidation of the Musonoi deposit in Katanga, Africa.
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The name, for the biblical "Eve", comes from its structural similarities to adamite and is also a reference to its apple-green color. It can also be pale yellow. Eveite is an orthorhombic mineral, which means it has three crystallographic axes of unequal lengths which are at 90° to one another. Eveite is anisotropic, which means that its physical and optical properties differ with respect to direction.
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Minyulite is a rare phosphate mineral with a chemical formula of KAl2(OH,F)(PO4)2·4(H2O). It occurs as groups of radiating fine fibrous crystals within rock cracks of phosphatic ironstone. Minyulite belongs to the orthorhombic crystal system. This indicates that it has three axes of unequal length yet all are perpendicular to each other. Its cell constants are a=9.35, b=9.74 c=5.52.
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This transition occurs without change in volume, but the enthalpy increases by 3.66 kJ/mol. Upon further compression to 25 GPa, berkelium transforms to an orthorhombic γ-berkelium structure similar to that of α-uranium. This transition is accompanied by a 12% volume decrease and delocalization of the electrons at the 5f electron shell. No further phase transitions are observed up to 57 GPa.
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In the absence of elements other than calcium, aluminium, iron and oxygen, calcium aluminoferrite forms a solid solution series of formula Ca2(AlxFe1−x)2O5 for all values of x in the range 0–0.7.H. F. W. Taylor, Cement Chemistry, Academic Press, 1990, . Compositions with x > 0.7 do not exist at ordinary pressures (see dicalcium aluminate). The crystal is orthorhombic, and is normally lath-like.
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The formations of colimaite have been described as hedgehog–like particles due to the acicular habit of extremely fine needles forming the aggregates. The size of these aggregates range from 10 to 100 µm. The needles themselves have been measured up to 50 µm in length and 20 µm in width. Although colimaite belongs to the orthorhombic crystal class, their crystallographic forms were not observed.
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It crystallizes in the orthorhombic crystal system (plutonium tribromide-type) in the space group Ccmm with the lattice parameters a = 432.8 pm, b = 1401.1 pm, and c = 1000.5 pm and four formula units per unit cell.J. H. Levy, J. C. Taylor, P. W. Wilson: "The Structure of Uranium(III) Triiodide by Neutron Diffraction", in: Acta Crystallogr. B, 1975, 31, S. 880–882 (). Uranium triiodide is Lewis acidic.
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Zoisite, first known as saualpite, after its type locality, is a calcium aluminium hydroxy sorosilicate belonging to the epidote group of minerals. Its chemical formula is Ca2Al3(SiO4)(Si2O7)O(OH). Zoisite occurs as prismatic, orthorhombic (2/m 2/m 2/m) crystals or in massive form, being found in metamorphic and pegmatitic rock. Zoisite may be blue to violet, green, brown, pink, yellow, gray, or colorless.
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The unit cell is orthorhombic and its most salient feature is four boron-containing icosahedra. Each icosahedron contains 12 boron atoms. Eight more boron atoms connect the icosahedra to the other elements in the unit cell. The occupancy of metal sites in the lattice is lower than one, and thus, while the material is usually identified with the formula AlMgB14, its chemical composition is closer to Al0.75Mg0.75B14.
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Copper(II) chlorate commonly crystallizes as a tetrahydrate, though a hexahydrate is also known. Tetraaquacopper(II) chlorate, Cu(ClO3)2·4H2O, has an orthorhombic crystal structure. Each copper atom is octahedrally coordinated, surrounded by four oxygen atoms of water, and two oxygen atoms from chlorate groups, which are opposite each other. Water is closer to the copper than chlorate, 1.944 Å compared to 2.396 Å, exhibiting the Jahn-Teller effect.
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Allanpringite is a phosphate mineral named after Australian mineralogist Allan Pring, South Australian Museum. Allanpringite is a Fe3+ analogue Al-phosphate mineral wavellite, but it has a different crystal symmetry – monoclinic instead of orthorhombic in wavellite. It forms needle-like crystals, which are always twinned and form parallel bundles up to about 2 mm long. They are often found in association with other iron phosphates in abandoned iron mines.
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Moolooite is a rare blue-green mineral with the formula Cu++(C2O4)·n(H2O) (n<1) (copper oxalate hydrate). It was discovered by Richard M Clarke and Ian R Williams in Bunbury Well, Mooloo Downs station, Murchison, Western Australia in 1986. It has an orthorhombic crystalline structure, and is formed by the interaction of bird guano with weathering copper sulfides. It is used in plastics to color them blueish-green.
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Zykaite or zýkaite is a grey-white mineral consisting of arsenic, hydrogen, iron, sulfur and oxygen with formula: Fe3+4(AsO4)3(SO4)(OH)·15(H2O).Webmineral data This dull mineral is very soft with a Mohs hardness of only 2 and a specific gravity of 2.5. It is translucent and crystallizes in the orthorhombic crystal system.Handbook of Mineralogy Its common associates include limonite, gypsum, scorodite, quartz and arsenopyrite.
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The self-assembly characteristics change in case of alkyl chain derivatives of c-HBC into orthorhombic crystalline cables which act as p-type semiconductors. The contorted peripheral edges of these molecules serve to provide unique intermolecular contacts which make these molecules efficient in charge transport. The tetra-dodecaloxy side chains in c-HBC promotes the self-assembly. These materials are deposited in the form of columnar hexagonal liquid crystals.
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It is represented by the vertices and edges of the quarter cubic honeycomb, filling space by regular tetrahedra and truncated tetrahedra. It contains four sets of parallel planes of points and lines, each plane being a two dimensional kagome lattice. A second expression in three dimensions has parallel layers of two dimensional lattices and is called an orthorhombic- kagome lattice. The trihexagonal prismatic honeycomb represents its edges and vertices.
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Sodium thiocyanate (sometimes called sodium sulphocyanide) is the chemical compound with the formula NaSCN. This colorless deliquescent salt is one of the main sources of the thiocyanate anion. As such, it is used as a precursor for the synthesis of pharmaceuticals and other specialty chemicals. Thiocyanate salts are typically prepared by the reaction of cyanide with elemental sulfur: :8 NaCN + S8 -> 8 NaSCN Sodium thiocyanate crystallizes in an orthorhombic cell.
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Niter is a colorless to white mineral crystallizing in the orthorhombic crystal system. It usually is found as massive encrustations and efflorescent growths on cavern walls and ceilings where solutions containing alkali potassium and nitrate seep into the openings. It occasionally occurs as prismatic acicular crystal groups, and individual crystals commonly show twinning. Niter and other nitrates can also form in association with deposits of guano and similar organic materials.
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The structure of nickel chromate is the same as for chromium vanadate, CrVO4. Crystals have an orthorhombic structure with unit cell sizes a = 5.482 Å, b = 8.237 Å, c = 6.147 Å. The cell volume is 277.6 Å3 with four formula per unit cell. Nickel chromate is dark in colour, unlike most other chromates which are yellow. The infrared spectrum of nickel chromate show two sets of absorption bands.
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The tetragonal form of YBCO is insulating and does not superconduct. Increasing the oxygen content slightly causes more of the O(1) sites to become occupied. For x < 0.65, Cu-O chains along the b axis of the crystal are formed. Elongation of the b axis changes the structure to orthorhombic, with lattice parameters of a = 3.82, b = 3.89, and c = 11.68 Å. Optimum superconducting properties occur when x ~ 0.07, i.e.
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The crystal structure of Sc2S3 is closely related to that of sodium chloride, in that it is based on a cubic close packed array of anions. Whereas NaCl has all the octahedral interstices in the anion lattice occupied by cations, Sc2S3 has one third of them vacant. The vacancies are ordered, but in a very complicated pattern, leading to a large, orthorhombic unit cell belonging to the space group Fddd.
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The uptake and loss of oxygen are reversible in YBa2Cu3O7−x. A fully oxygenated orthorhombic YBa2Cu3O7−x sample can be transformed into tetragonal YBa2Cu3O6 by heating in a vacuum at temperature above 700 °C. The preparation of Bi-, Tl- and Hg-based high-Tc superconductors is more difficult than the YBCO preparation. Problems in these superconductors arise because of the existence of three or more phases having a similar layered structure.
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It condenses at −34.04 °C to an amber-coloured liquid and freezes at −101.5 °C into a yellow crystalline solid. The solid form (density 1.9 g/cm−3) has an orthorhombic crystalline structure and is soft and easily crushed. Chlorine is an insulator in all of its forms. It has a high ionisation energy (1251.2 kJ/mol), high electron affinity (349 kJ/mol; higher than fluorine), and high electronegativity (3.16).
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Molar volume vs. pressure at room temperature Wadsleyite crystallizes in the orthorhombic crystal system and has a unit cell volume of 550.00 Å3. Its space group is Imma and its cell parameters are a = 5.6921 Å, b = 11.46 Å and c = 8.253 Å (Price et al. 1983); an independent study found the cell parameters to be a = 5.698 Å, b = 11.438 Å and c = 8.257 Å (Horiuchi and Sawamoto, 1981).
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The mineral marcasite, sometimes called “white iron pyrite”, is iron sulfide (FeS2) with orthorhombic crystal structure. It is physically and crystallographically distinct from pyrite, which is iron sulfide with cubic crystal structure. Both structures do have in common that they contain the disulfide S22− ion having a short bonding distance between the sulfur atoms. The structures differ in how these di-anions are arranged around the Fe2+ cations.
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The room temperature form of TlI is yellow and has an orthorhombic structure which can be considered to be a distorted NaCl structure. The distorted structure is believed to be caused by favourable thallium-thallium interactions, the closest Tl-Tl distance is 383 pm. At 175 °C the yellow form transforms to a red CsCl form. This phase transition is accompanied by about two orders of magnitude jump in electrical conductivity.
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This is called parallel extinction. All uniaxial minerals display parallel extinction, but so do orthorhombic biaxial minerals such as olivine and orthopyroxenes. The refractive index of todorokite has not been determined, except insofar as it is very high; the original report gave it as greater than 1.74, and a later investigation put it even higher, greater than 2.00. For comparison, diamond has a refractive index of 2.42 and quartz 1.54.
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Iridium disulfide is the binary inorganic compound with the formula IrS2. Prepared by the direct reaction of the elements, the compound adopts the pyrite crystal structure at high pressure. At normal atmospheric pressures, an orthorhombic polymorph is observed.. The high- and low-pressure forms both feature octahedral Ir centers, but the S–S distances are pressure dependent. Although not practical, IrS2 is a highly active catalyst for hydrodesulfurization.
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The article about peterbaylissite written by Roberts et al. (1995)Roberts, A.C., Ercit, T.S., Groat, L.A., Criddle, A.J., Erd, R.C., and Williams, R.S. (1995) Peterbaylissite, Hg31+(CO3)(OH)∙2H2O, a new mineral species from the Clear Creek claim, San Benito County, California. The Canadian Mineralogist, 33, 47-53. describe this mineral as orthorhombic with the point group 2/m, 2/m, 2/m, meanwhile clearcreekite is monoclinic; 2/m.
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Anthonyite occurs as an alteration of native copper in basalt in fractures and cavities by circulation of chloride rich groundwater or connate fluids. The similar orthorhombic mineral calumetite occurs by the same process. It occurs associated with tremolite, quartz, epidote, monazite, native copper, cuprite and paratacamite in the Centennial mine area. It also occurs in the Cole mine, at Bisbee, Cochise County, Arizona; and Villa Hermosa, Sonora, Mexico.
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Silver chromate is produced by the salt metathesis reaction of potassium chromate and silver nitrate in purified water - the silver chromate will precipitate out of the aqueous reaction mixture. The solubility of silver chromate is very low (Ksp = 1.1×10−12 or 6.5×10−5 mol/L). It crystallzes in the orthorhombic space group Pnma, with two distinct coordination environments for the silver ions, one tetragonal bipyramidal and the other distorted tetrahedral.
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Olivine's crystal structure incorporates aspects of the orthorhombic P Bravais lattice, which arise from each silica (SiO4) unit being joined by metal divalent cations with each oxygen in SiO4 bound to three metal ions. It has a spinel-like structure similar to magnetite but uses one quadrivalent and two divalent cations M22+ M4+O4 instead of two trivalent and one divalent cations.Ernst, W. G. Earth Materials. Englewood Cliffs, NJ: Prentice-Hall, 1969. p.
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Gottlobite, ), is a mineral found as isolated crystals or isometric grains of orange or orange-brown color. The size of the crystals are a half millimeter in diameter and are part of the orthorhombic crystal system. Gottlobite forms a solid solution with adelite, which is an end member composition of CaMg(VO4)(OH), as well as being classified in the adelite group. Gottlobite is also part of the vanadates and arsenates group.
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Laurionite (PbCl(OH)) is a lead halide mineral. It forms colorless to white crystals in the orthorhombic crystal system and is dimorphous with paralaurionite, both members of the matlockite group. It was first described in 1887 for an occurrence in the Laurium District, Attica, Greece, and named after the town Laurium. It occurs as an oxidation product in lead ore deposits, and is also produced on lead-bearing slag by reaction with saline solutions.
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At the time when the term became common in jewelry making, "marcasite" referred to all iron sulfides including pyrite, and not to the orthorhombic FeS2 mineral marcasite which is lighter in color, brittle and chemically unstable, and thus not suitable for jewelry making. Marcasite jewelry does not actually contain the mineral marcasite. The specimens of pyrite, when it appears as good quality crystals, are used in decoration. They are also very popular in mineral collecting.
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Zinc hydroxide Zn(OH)2 is an inorganic chemical compound. It also occurs naturally as 3 rare minerals: wülfingite (orthorhombic), ashoverite and sweetite (both tetragonal). Like the hydroxides of other metals, such as lead, aluminium, beryllium, tin and chromium, Zinc hydroxide (and Zinc oxide), is amphoteric. Thus it will dissolve readily in a dilute solution of a strong acid, such as HCl, and also in a solution of an alkali such as sodium hydroxide.
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Lavendulan is a blue or greenish blue translucent mineral, with a vitreous to waxy luster, satiny in aggregates, and a light blue streak. It occurs as thin botryoidal crusts of minute radiating fibers or as thin rectangular, pseudo-orthorhombic plates, with cleavage in three directions, nearly perfect perpendicular to the b crystal axis, and distinct perpendicular to the a and c axes. Twinning is common. The mineral is brittle, with an uneven fracture.
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For langite the angle β is very close to 90°, so the unit cell is almost brick- shaped (as for the orthorhombic system). Different sources give slightly different values for the unit cell parameters, but they all fall within the ranges a = 7.118 Å to 7.137 Å, b = 6.031 Å to 6.034 Å, c = 11.209 Å to 11.217 Å, β = 90.00 to 90.02°, Z (the number of formula units per unit cell) = 2.
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As a result, it has been shown that two sets of covalent bonds compose the bonds forming the compound. One set is the three center Pt-Si-Pt bond, and the other set the two center Pt-Si bonds. Each silicon atom in the compound has one three center bond and two two center bonds. The thinnest film of PtSi would consist of two alternating planes of atoms, a single sheet of orthorhombic structures.
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The crystal structure of americium changes with pressure and temperature. When compressed at room temperature to 5 GPa, α-Am transforms to the β modification, which has a face-centered cubic (fcc) symmetry, space group Fmm and lattice constant a = 489 pm. This fcc structure is equivalent to the closest packing with the sequence ABC. Upon further compression to 23 GPa, americium transforms to an orthorhombic γ-Am structure similar to that of α-uranium.
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Germanium telluride (GeTe) is a chemical compound of germanium and tellurium and is a component of chalcogenide glasses. It shows semimetallic conduction and ferroelectric behaviour. Germanium telluride exists in three major crystalline forms, room-temperature α (rhombohedral) and γ (orthorhombic) structures and high-temperature β (cubic, rocksalt-type) phase; α phase being most phase for pure GeTe below the ferroelectric Curie temperature of approximately 670 K. Doped germanium telluride is a low temperature superconductor.
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An example of the triclinic crystals, microcline Triclinic (a ≠ b ≠ c and α ≠ β ≠ γ ) In crystallography, the triclinic (or anorthic) crystal system is one of the 7 crystal systems. A crystal system is described by three basis vectors. In the triclinic system, the crystal is described by vectors of unequal length, as in the orthorhombic system. In addition, the angles between these vectors must all be different and may not include 90°.
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Autunite (hydrated calcium uranyl phosphate), with formula Ca(UO2)2(PO4)2·10–12H2O, is a yellow-greenish fluorescent phosphate mineral with a hardness of 2–. Autunite crystallizes in the orthorhombic system and often occurs as tabular square crystals, commonly in small crusts or in fan- like masses. Due to the moderate uranium content of 48.27% it is radioactive and also used as uranium ore. Autunite fluoresces bright green to lime green under UV light.
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Heating of boric acid at 80-100 °C releases water to give orthorhombic metaboric acid:H. J. Becher "Metaboric Acid" Handbook of Preparative Inorganic Chemistry, 2nd Ed. Edited by G. Brauer, Academic Press, 1963, NY. Vol. 1. p. 791. 3 B(OH)3 → (BOH)3O3 \+ 3 H2O This form is molecular, consisting of discrete trimers. This molecule has C3h symmetry and forms a sheet-like structure, similar to that of boric acid itself.
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Yoshida et al., 724–726. The greenish-brown NpO2 is very stable over a large range of pressures and temperatures and does not undergo phase transitions at low temperatures. It does show a phase transition from face-centered cubic to orthorhombic at around 33-37GPa, although it returns to is original phase when pressure is released. It remains stable under oxygen pressures up to 2.84 MPa and temperatures up to 400 °C.
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It is the only element, apart from mercury, known to be a liquid at room temperature. The solid form, like chlorine, has an orthorhombic crystalline structure and is soft and easily crushed. Bromine is an insulator in all of its forms. It has a high ionisation energy (1139.9 kJ/mol), high electron affinity (324 kJ/mol), and high electronegativity (2.96). Bromine is a strong oxidising agent (Br2 \+ 2e → 2HBr = 1.07 V at pH 0).
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Boehmite or böhmite is an aluminium oxide hydroxide (γ-AlO(OH)) mineral, a component of the aluminium ore bauxite. It is dimorphous with diaspore. It crystallizes in the orthorhombic dipyramidal system and is typically massive in habit. It is white with tints of yellow, green, brown or red due to impurities. It has a vitreous to pearly luster, a Mohs hardness of 3 to 3.5 and a specific gravity of 3.00 to 3.07.
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Figure 4a and 4b, show the mineral cordierite, which is also considered to be a diagnostic mineral for peraluminous S-type granites in the Strathbogie Granite (sample CV-142). Subhedral cordierite phenocryst shown here is colorless in plane polarized light, but can display a light blue color in some minerals, and is grey in cross-polarized light. It is an orthorhombic mineral and displays a prismatic crystal form with imperfect cleavage. Figure 4a.
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Kostovite is a rare orthorhombic-pyramidal gray white telluride mineral containing copper and gold with chemical formula AuCuTe4. National Natural History Museum, Sofia, Bulgaria It was discovered by Bulgarian mineralogist Georgi Terziev (Георги Терзиев) (1935–1972), who named it in honor of his professor Ivan Kostov (Иван Костов) (1913–2004). In 1965 kostovite was approved as a new species by the International Mineralogical Association. The type locality is the Chelopech copper ore deposit, Bulgaria.
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This can be explained by the orthorhombic structure. When looking at the boron and osmium atoms in the a and b directions, they are arranged in a way that is offset from one another. Therefore, when they are compressed they are not pushed right up against one another. Electrostatic repulsion is the force that maximizes the materials incompressibility and so in this case the electrostatic repulsion is not taken full advantage of.
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Cluster of scolecite needles Scolecite commonly occurs as sprays of thin, prismatic needles, frequently flattened on one side, with slanted terminations and striated parallel to the length of the needles. The crystals appear to be pseudo-orthorhombic or pseudo-tetragonal, and may be square in cross section. It also occurs as radiating groups and fibrous masses. Epitaxial intergrowths (intergrowths of two different crystalline substances in a non-random way) with mesolite, Na2Ca2Al6Si9O30·8H2O, are common.
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Idrialite is a rare hydrocarbon mineral with approximate chemical formula C22H14. Idrialite usually occurs as soft orthorhombic crystals, is usually greenish yellow to light brown in color with bluish fluorescence. It is named after the Idrija region of Slovenia, where its occurrence was first described. The mineral has also been called idrialine, and branderz in German It has also been called inflammable cinnabar due to its combustibility and association with cinnabar ores in the source locality.
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Scotlandite is a sulfite compared with chemically related compounds, it is very close to the value of anglesite (6.38 g cm−3), but distinctly different from that of lanarkite (6.92 g cm−3). Orthorhombic lead sulfite is of higher density (Dmeas = 6.54, calculated Dx = 6.56 g cm−3), and has the same chemical properties as well. The empirical chemical formula for scotlandite calculated on the basis of Pb+S = 2, is Pbl.06S0.94O2.94 or more ideally PbSO3.
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Serpierite is a hydrated sulfate with the formula Ca(Cu,Zn)4(SO4)2(OH)6.3H2O with molar mass 644.32 g and calculated density 3.08 g/cm3. It belongs to the monoclinic crystal system, point group 2/m and space group C2/c. It is pseudo-orthorhombic and isostructural with aldridgeite. The unit cell has side a of length 22.2 Å, side c of length 21.9 Å and the angle β between them equal to 113.4°.
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The mineral belongs in the orthorhombic crystal system, or the monoclinic with β (the angle between the a and c crystal axes) close to 90o. The space group is unknown, but assumed to be either P21/m, P21 or P2221. The structure is similar to that of hydrozincite. There are four formula units per unit cell (Z = 4) and the lengths of the sides of the unit cell are a = 15.724 Å, b = 6.256 Å and c = 5.427 Å.
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This compound is not commonly available commercially. It may be prepared by the reaction of tetrachloroauric acid with tetrahydrothiophene: : HAuCl4 \+ 2 SC4H8 \+ H2O → AuCl(SC4H8) + OSC4H8 \+ 3 HCl The complex adopts a linear coordination geometry, which is typical of most gold(I) compounds. It crystallizes in the orthorhombic space group Pmc21 with a = 6.540(1) Å, b = 8.192(1) Å, c = 12.794(3) Å with Z = 4 formula units per unit cell. The bromide congener is isostructural.
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The light passing through the mineral will therefore have different colors when it is viewed from different angles, making the stone seem to be of different colors. Tetragonal, trigonal, and hexagonal minerals can only show two colors and are called dichroic. Orthorhombic, monoclinic, and triclinic crystals can show three and are trichroic. For example, hypersthene, which has two optical axes, can have a red, yellow, or blue appearance when oriented in three different ways in three-dimensional space.
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Collection specimens must be kept in a sealed argon environment. It has a Hermann–Mauguin notation of mm2 and the respective space group is Cmc21. In nature Nyerereite is naturally twinned and is pseudohexagonal with triad twinning; meaning that this is a six sided crystal that apparently has a hexagonal shape but is not in the hexagonal system. Triad twinning is the intergrowth of three orthorhombic crystals that turn at their center and form hexagonally shaped crystals.
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Xocomecatlite is a rare tellurate mineral with formula: Cu3(TeO4)(OH)4. It is an orthorhombic mineral which occurs as aggregates or spherules of green needlelike crystals. It was first described in 1975 for an occurrence in the Oriental mine near Moctezuma, Sonora, Mexico. It has also been reported from the Centennial Eureka mine in the Tintic District, Juab County, Utah and the Emerald mine of the Tombstone District, Cochise County, Arizona in the United States.
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The rutile precipitates all align perpendicularly with respect to cat's eye effect. It is reasoned that the lattice parameter of the rutile matches only one of the three orthorhombic crystal axes of the chrysoberyl, resulting in preferred alignment along that direction. Yellow- green quartz cabochon showing cat's-eye effect. The effect can be likened to the sheen off a spool of silk: The luminous streak of reflected light is always perpendicular to the direction of the fibres.
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This trick is applicable to molecules that have acidic hydrogen atoms, e.g. phenols. Up to now, several modifications of Ph3PO have been found: For example, a monoclinic form crystalizes in the space group P21/c with Z = 4 and a = 15.066(1) Å, b = 9.037(2) Å, c = 11.296(3) Å, and β = 98.47(1)°. The orthorhombic modification crystallizes in the space group Pbca with Z = 4 and 29.089(3) Å, b = 9.1347(9), c = 11.261(1) Å.
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Cummingtonite ( ) is a metamorphic amphibole with the chemical composition , magnesium iron silicate hydroxide. Monoclinic cummingtonite is compositionally similar and polymorphic with orthorhombic anthophyllite, which is a much more common form of magnesium-rich amphibole, the latter being metastable. Cummingtonite shares few compositional similarities with alkali amphiboles such as arfvedsonite, glaucophane-riebeckite. There is little solubility between these minerals due to different crystal habit and inability of substitution between alkali elements and ferro-magnesian elements within the amphibole structure.
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Germanium selenide is a chemical compound with the formula GeSe. It exists as black crystalline powder having orthorhombic (distorted NaCl-type) crystal symmetry; at temperatures ~650 °C, it transforms into the cubic NaCl structure. To grow GeSe crystals, GeSe powder is vaporized at the hot end of a sealed ampule and allowed to condense at the cold end. Usual crystals are small and show signs of irregular growth, caused mainly by convective motion in the gaseous medium.
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Perite is a mineral that has a general chemical formula of PbBiO2Cl. The name is given for Per Adolf Geijer, a Swedish economic geologist with the Geological Survey of Sweden, who discovered the mineral in 1960 outside of Langban, Sweden. Perite is orthorhombic, which means crystallographically, it contains three axes of two of equal length (the bases a and b) and one of a little longer or shorter length. All three bases intersect at a 90° angles.
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Carminite belongs to the orthorhombic crystal class (2/m 2/m 2/m) and has space group C ccm or C cc2.Finney J J (1963) American Mineralogist 48: 1-13 The structure consists of linked octahedra of iron surrounded by oxygen and hydroxyl which are aligned parallel to the c axis. They are connected together in the direction of the an axis by arsenate tetrahedra (arsenic surrounded by 4 oxygen). Coordination about the lead atoms is eight-fold.
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Triclinic crystals (and orthorhombic and monoclinic crystals) have two directions in which light travels with zero birefringence; these directions are called the optic axes, and the crystal is said to be biaxial. Talmessite is triclinic, so it is biaxial. The speed of a ray of light travelling through the crystal differs with direction. The direction of the fastest ray is called the X direction and the direction of the slowest ray is called the Z direction.
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Americium monosilicide (AmSi) and "disilicide" (nominally AmSix with: 1.87 < x < 2.0) were obtained by reduction of americium(III) fluoride with elementary silicon in vacuum at 1050 °C (AmSi) and 1150−1200 °C (AmSix). AmSi is a black solid isomorphic with LaSi, it has an orthorhombic crystal symmetry. AmSix has a bright silvery lustre and a tetragonal crystal lattice (space group I41/amd), it is isomorphic with PuSi2 and ThSi2. Borides of americium include AmB4 and AmB6.
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Laplandite has a general formula of Na4CeTiPO4Si7O18•5H2O, and is found primarily in igneous rocks. This silicate mineral has been found as inclusions in pegmatites, primarily in the Kola Peninsula in Lappland, where the mineral's name gets its origin. Laplandite is orthorhombic, which states that crystallographically, it contains three axes of unequal lengths that all intersect at 90 degrees, perpendicular to one another. The shape of the crystal is bipyramidal, and is similar in structure to olivine or aragonite.
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This animation illustrates the full shape memory effect: The shape memory effect (SME) occurs because a temperature-induced phase transformation reverses deformation, as shown in the previous hysteresis curve. Typically the martensitic phase is monoclinic or orthorhombic (B19' or B19). Since these crystal structures do not have enough slip systems for easy dislocation motion, they deform by twinning—or rather, detwinning. Martensite is thermodynamically favored at lower temperatures, while austenite (B2 cubic) is thermodynamically favored at higher temperatures.
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Calcite is a carbonate mineral (CaCO3) with a rhombohedral crystal structure. Aragonite is an orthorhombic polymorph of calcite. An initial step in identifying a mineral is to examine its physical properties, many of which can be measured on a hand sample. These can be classified into density (often given as specific gravity); measures of mechanical cohesion (hardness, tenacity, cleavage, fracture, parting); macroscopic visual properties (luster, color, streak, luminescence, diaphaneity); magnetic and electric properties; radioactivity and solubility in hydrogen chloride ().
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Orthorhombic ferroselite and its isometric polymorph dzharkenite are iron selenides of general formula FeSe2 precipitated under reducing conditions in anoxic environments. They are a source of selenium in the Rocky Mountains where selenium occurrence is associated with Upper Cretaceous shale deposits. In the frame of safety assessment calculations made for deep disposal of high- level radioactive waste, ferroselite and dzharkenite are also considered in geochemical calculations as one of the mineral phases limiting the solubility of Selenium-79.
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Kornerupine (also called Prismatine) is a rare boro-silicate mineral with the formula (Mg,Fe2+)4(Al,Fe3+)6(SiO4,BO4)5(O,OH)2. It crystallizes in the orthorhombic - dipyramidal crystal system as brown, green, yellow to colorless slender tourmaline like prisms or in massive fibrous forms. It has a Mohs hardness of 7 and a specific gravity of 3.3 to 3.34. Its indices of refraction are nα=1.660 - 1.671, nβ=1.673 - 1.683 and nγ=1.674 - 1.684.
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The ferrierite group of zeolite minerals (the FER structure) consists of three very similar species: ferrierite-Mg, ferrierite-Na, and ferrierite-K, based on the dominant cation in the A location. ferrierite-Mg and ferrierite-K are orthorhombic minerals and ferrierite-Na is monoclinic with highly variable cationic composition . Calcium and other ions are often also present. They are found in vitreous to pearly, often radiating, spherical aggregates of thin blade-shaped transparent to translucent crystals.
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The amphibole group consists of an orthorhombic and monoclinic series – hornblendes and tschermakite both belong to the latter crystal structure. The crystal group of tschermakite is 2/m. Tschermakite and all the hornblende varieties are inosilicates, and like the other rock forming amphiboles are double chain silicates (Klein and Hurlbut, 1985). The amphibole structure is characterized by its two double chains of SiO4 tetrahedra (T1 and T2) sandwiching in a strip of cations (M1, M2 and M3 octahedra).
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Uranium diselenide is a compound of uranium and selenium. It has a β form that has orthorhombic crystal system. The family of crystals it matches is PbCl2. The dimensions of the unit cell are a: 7.455 Å, b: 4.2320 Å, c= 8.964 Å. The compound has the unusual property of ferromagnetism, but only if the temperature is below 14 K. Tellurium can be substituted for selenium in varying quantities, expanding the lattice and increasing the ferromagnetic Curie temperature.
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According to Subbarao, changbaiite is orthorhombic at 25 °C with unit cell dimensions of a=17.65, b=17.91, c=7.736 Å and because its big unit cell size it is difficult to do a full structure analysis of PbNb2O6. Changbaiite structure is composed of NbO6 octahedral crystals connected at their corners forming circles of 3 to 5 octahedral. The NbO6 "cage" has coordination of 8 around oxygen. and the "tunnels" have a coordination of 10 around the Pb2+.
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Black phosphorus has an orthorhombic pleated honeycomb structure and is the least reactive allotrope, a result of its lattice of interlinked six-membered rings where each atom is bonded to three other atoms. Black and red phosphorus can also take a cubic crystal lattice structure. The first high-pressure synthesis of black phosphorus crystals was made by the physicist Percy Williams Bridgman in 1914. A recent synthesis of black phosphorus using metal salts as catalysts has been reported.
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Billietite is an uncommon mineral of Uranium that contains Barium. It has the chemical formula: Ba(UO2)6O4(OH)6•8H2O. It usually occurs as clear yellow orthorhombic crystals.M. Katherine Pagoaga, Daniel E, Appleman, & James M. Stewart "Crystal structures and crystal chemistry of the uranyl oxide hydrates becquerelite, billietite, and protasite" American Mineralogist, Volume 72, pages 1230-1238, 1987 Billietite is named after Valere Louis Billiet (1903–1944), Belgian crystallographer at the University of Ghent, Ghent, Belgium.
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The lack of symmetry via inversion centers can allow for areas of the crystal to interact differently with incoming light. The wavelength, frequency and intensity of light is subject to change as the electromagnetic radiation interacts with different energy states throughout the structure. Potassium titanyl phosphate, KTiOPO4 (KTP) crystalizes in the noncentrosymmetric, orthorhombic Pna21 space group, and is a useful non-linear crystal. KTP is used for frequency-doubling neodymium- doped lasers, utilizing a nonlinear optical property known as second-harmonic generation.
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Enstatite and the other orthorhombic pyroxenes are distinguished from those of the monoclinic series by their optical characteristics, such as straight extinction, much weaker double refraction and stronger pleochroism. They also have a prismatic cleavage that is perfect in two directions at 90 degrees. Enstatite is white, gray, greenish, or brown in color; its hardness is 5–6 on the Mohs scale, and its specific gravity is 3.2–3.3. This prismatic form is used in gemstones, and for academic purposes.
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The thermodynamically stable form of CaCO3 under normal conditions is hexagonal β-CaCO3 (the mineral calcite). Other forms can be prepared, the denser (2.83 g/cm3) orthorhombic λ-CaCO3 (the mineral aragonite) and hexagonal μ-CaCO3, occurring as the mineral vaterite. The aragonite form can be prepared by precipitation at temperatures above 85 °C, the vaterite form can be prepared by precipitation at 60 °C. Calcite contains calcium atoms coordinated by six oxygen atoms, in aragonite they are coordinated by nine oxygen atoms.
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Ruthenium hexafluoride is a dark brown crystalline solid that melts at 54 °C. The solid structure measured at −140 °C is orthorhombic space group Pnma. Lattice parameters are a = 9.313 Å, b = 8.484 Å, and c = 4.910 Å. There are four formula units (in this case, discrete molecules) per unit cell, giving a density of 3.68 g·cm−3. The RuF6 molecule itself (the form important for the liquid or gas phase) has octahedral molecular geometry, which has point group (Oh).
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Like other members of the group monticellite and kirschsteinite have orthorhombic unit cells (space group Pbnm) shown in Figure 1. Iron and magnesium ions are located on the M1 inversion sites and calcium ions occupy the M2 site on mirror planes. The unit cell is somewhat larger than for the calcium free olivines forsterite and fayalite with :a = 0.4815 nm, :b = 1.108 nm and :c = 0.637 nm, and for monticellite :a = 0.4875 nm, :b = 1.1155 nm and :c = 0.6438 nm.
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Each of the other boron atoms has a side oxygen connection that is shared with other of the building blocks. One of those boron atoms has a fluorine attached. The building block connect into two interpenetrating three- dimensional structures. The crystal structure is orthorhombic with space group Pbca; MW 408.24; a=10.885, b=9.108, c=13.576 Å, Z=8 Volume= 1345.9 Å3 Density = 2.938 ;It is a positive biaxial crystal; Birefringence is 0.0685 at 1064 nm (NIR) to 0.0737 at 400 nm.
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It displays strong pleochroism, the pleochroic colors being usually green, yellow and brown. Clinozoisite is green, white or pale rose-red group species containing very little iron, thus having the same chemical composition as the orthorhombic mineral zoisite. The name, due to Haüy, is derived from the Greek word "epidosis" (ἐπίδοσις) which means "addition" in allusion to one side of the ideal prism being longer than the other. Epidote from Alaska Epidote is an abundant rock-forming mineral, but one of secondary origin.
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YB50 decomposes at ~1750 °C without melting that hinders growth of single crystals from the melt. Small addition of silicon made YB50 to melt without decomposition, and so enabled single-crystal growth from the melt and single-crystal structure analysis. The structure analysis indicated that YB41Si1.2 has not the γ-AlB12-type lattice but a rare orthorhombic crystal structure (space group: Pbam, No. 55) with lattice constants of a = 1.674(1) nm, b = 1.7667(1) nm and c = 0.9511(7) nm.
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At Low temperatures, where the concentration of hole carriers is less than 1.5x1020 cm−3 , Tin Telluride exists in rhombohedral phase also known as α-SnTe. At room temperature and atmospheric pressure, Tin Telluride exists in NaCl-like cubic crystal phase, known as β-SnTe. While at 18 kbar pressure, β-SnTe transforms to γ-SnTe, orthorhombic phase, space group Pnma. This phase change is characterized by 11 percent increase in density and 360 percent increase in resistance for γ-SnTe.
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Silicene, a two-dimensional allotrope of silicon, with a hexagonal honeycomb structure similar to that of graphene, was observed in 2010. The synthesis of an orthorhombic allotrope Si24, was subsequently reported in 2014. At pressure of ~10–11 GPa, germanium transforms to a metallic phase with the same tetragonal structure as tin; when decompressed—and depending on the speed of pressure release—metallic germanium forms a series of allotropes that are metastable at ambient condition. Germanium also forms a graphene analogue, germanene.
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NaOH and its monohydrate form orthorhombic crystals with the space groups Cmcm (oS8) and Pbca (oP24), respectively. The monohydrate cell dimensions are a = 1.1825, b = 0.6213, c = 0.6069 nm. The atoms are arranged in a hydrargillite-like layer structure /O Na O O Na O/... Each sodium atom is surrounded by six oxygen atoms, three each from hydroxyl anions and three from water molecules. The hydrogen atoms of the hydroxyls form strong bonds with oxygen atoms within each O layer.
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Both square SnSe nanostructures and single-layer SnSe nanostructures have been prepared. Historically, phase- controlled synthesis of 2D tin selenide nanostructures is quite difficult. Sheet-like nanocrystalline SnSe with an orthorhombic phase has been prepared with good purity and crystallization via a reaction between a selenium alkaline aqueous solution and tin(II) complex at room temperature under atmospheric pressure. SnSe nanocrystals have also been synthesized by a gas- phase laser photolysis reaction that used Sn(CH3)4 and Se(CH3)2 as precursors.
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It belongs in the biaxial group, because it is an orthorhombic mineral. Under plane polarized light, zorite displays different colors depending on the angle that the light hits the mineral. This quality is called pleochroism and zorite is rose along the x-axis, colorless along the y-axis, and bluish along the z-axis.Zorite Mineral Data The index of refraction of zorite is 1.59,mineral general info which is the velocity of light through vacuum over the velocity of light through zorite.
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At −140 °C, it crystallizes in the orthorhombic space group Pnma. Lattice parameters are a = 9.394 Å, b = 8.543 Å, and c = 4.959 Å. There are four formula units (in this case, discrete molecules) per unit cell, giving a density of 3.50 g·cm−3. The fluorine atoms are arranged in the hexagonal close packing.J. H. Levy, J. C Taylor, A. B. Waugh: "Neutron Powder Structural Studies of UF6, MoF6 and WF6 at 77 K", in: Journal of Fluorine Chemistry, 1983, 23 (1), pp.
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Prehnite is an inosilicate of calcium and aluminium with the formula: Ca2Al(AlSi3O10)(OH)2. Limited Fe3+ substitutes for aluminium in the structure. Prehnite crystallizes in the orthorhombic crystal system, and most often forms as stalactitic or botryoidal aggregates, with only just the crests of small crystals showing any faces, which are almost always curved or composite. Very rarely will it form distinct, well-individualized crystals showing a square- like cross-section, including those found at the Jeffrey Mine in Asbestos, Quebec, Canada.
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When the saturation state is high, organisms can extract the calcium and carbonate ions from the seawater and form solid crystals of calcium carbonate. Ca2+(aq) \+ 2HCO3−(aq) → CaCO3(s) \+ CO2 \+ H2O The three most common calcium carbonate minerals are aragonite, calcite, and vaterite. Though these minerals have the same chemical formula (CaCO3), they are considered polymorphs because the atoms making up the molecules are stacked in different configurations. For example, aragonite minerals have an orthorhombic crystal lattice structure while calcite crystals have a trigonal structure.
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Osmium hexafluoride is a yellow crystalline solid that melts at 33.4 °C and boils at 47.5 °C. The solid structure measured at −140 °C is orthorhombic space group Pnma. Lattice parameters are a = 9.387 Å, b = 8.543 Å, and c = 4.944 Å. There are four formula units (in this case, discrete molecules) per unit cell, giving a density of 5.09 g·cm−3. The OsF6 molecule itself (the form important for the liquid or gas phase) has octahedral molecular geometry, which has point group (Oh).
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Greenwood and Earnshaw, pp. 804–09 The colour fades at low temperatures, so that solid chlorine at −195 °C is almost colourless. Like solid bromine and iodine, solid chlorine crystallises in the orthorhombic crystal system, in a layered lattice of Cl2 molecules. The Cl–Cl distance is 198 pm (close to the gaseous Cl–Cl distance of 199 pm) and the Cl···Cl distance between molecules is 332 pm within a layer and 382 pm between layers (compare the van der Waals radius of chlorine, 180 pm).
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This substance is transparent from 180 nm to 1000 nm (UV to NIR). Optically it is a positive biaxial. The birefringence is around 0.06 in the visible light region of the spectrum, but increases sharply in the UV t 0.093 at 200 nm. Crystal structure: Orthorhombic, Pbca a = 11.399 Å b = 9.429 Å c = 13.467(4) Å Volume 1447.4 Å3 Z=8, Calculated density = 3.133 g·cm‒3 PbB5O8F This compound has a building block consisting of B5O10F6− with a double boroxine ring with one shared boron.
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ScB14–xCx has an orthorhombic crystal structure with space group Imma (No. 74) and lattice constants of a = 0.56829(2), b = 0.80375(3) and c = 1.00488(4) nm. The crystal structure of ScB14–xCx is isotypic to that of MgAlB14 where Sc occupies the Mg site, the Al site is empty and the boron bridge site is a B/C mixed-occupancy site with the occupancy of B/C = 0.45/0.55. The occupancy of the Sc site in flux-grown single crystals is 0.964(4), i.e.
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Nevertheless, it was possible to verify that it is mainly composed of SiO2 with minor inclusions of Na2O (0.40 wt.%) and Al2O3 (1.14 wt.%). X-ray diffraction reveals that the mineral has scrutinyite (α-PbO2) type structure with an orthorhombic symmetry and Pbcn or Pb2n space group. Its lattice constants a = 4.097, b = 5.0462, c = 4.4946, Z = 4 correspond to the density of 4.294 g/cm3, which is among the highest for any forms of silica (for example, density of quartz is 2.65 g/cm3).
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LaYbO3 and other LaREO3 oxides (where RE=Ho, Y, Er, Tm, Yb, and Lu) compounds have an orthorhombic crystal structure with an internal symmetry described by the Pnma space group. The structure can be described by slightly distorted YbO6 octahedra tilted in the a−b+a− configuration according to Glazer's notation and antiparallel displaced La3+ ions. The rotation of the YbO6 octahedra reduces the coordination number of the La from 12 to 8. It exhibits exhibit a negative thermal expansion along the a and b axes.
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Arsenopyrite crystal from the Yaogangxian Mine, Hunan, China (size: 2.7 x 2.0 x 1.7 cm) Arsenopyrite crystallizes in the monoclinic crystal system and often shows prismatic crystal or columnar forms with striations and twinning common. Arsenopyrite may be referred to in older references as orthorhombic, but it has been shown to be monoclinic. In terms of its atomic structure, each Fe center is linked to three As atoms and three S atoms. The material can be described as Fe3+ with the diatomic trianion AsS3−.
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Iodine crystals Iodine, the rarest of the nonmetallic halogens, is a metallic looking solid that is moderately reactive, and has a density of 4.933 g/cm3. It melts at 113.7 °C to a brown liquid and boils at 184.3 °C to a violet-coloured vapour. It has an orthorhombic crystalline structure with a flaky habit. Iodine is semiconductor in the direction of its planes, with a band gap of about 1.3 eV and a conductivity of 1.7 × 10−8 S•cm−1 at room temperature.
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An acid sulfate, indium hydrogensulfate tetrahydrate with the formula HIn(SO4)2·4H2O crystallises in the orthorhombic system with unit cell dimensions a = 9.997 Å, b = 5.477 Å, c = 18.44 Å, with four of the formula per cell. The density is 2.50 cm−3. In the acid sulfate, two water molecules are linked to the indium atom and a hydronium ion H5O2 takes care of the proton. This is part of an acid sulfate family that includes Al, Ga, In, Tl(III), Fe(III) and Ti(III).
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Crystal structure of α-PbO2 Crystal structure of β-PbO2 Lead dioxide has two major polymorphs, alpha and beta, which occur naturally as rare minerals scrutinyite and plattnerite, respectively. Whereas the beta form had been identified in 1845, α-PbO2 was first identified in 1946 and found as a naturally occurring mineral 1988. The alpha form has orthorhombic symmetry, space group Pbcn (No. 60), Pearson symbol oP12, lattice constants a = 0.497 nm, b = 0.596 nm, c = 0.544 nm, Z = 4 (four formula units per unit cell).
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Iridium hexafluoride is a yellow crystalline solid that melts at 44 °C and boils at 53.6 °C. The solid structure measured at −140 °C is orthorhombic space group Pnma. Lattice parameters are a = 9.411 Å, b = 8.547 Å, and c = 4.952 Å. There are four formula units (in this case, discrete molecules) per unit cell, giving a density of 5.11 g·cm−3. The IrF6 molecule itself (the form important for the liquid or gas phase) has octahedral molecular geometry, which has point group (Oh).
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Todorokite is a rare complex hydrous manganese oxide mineral with the formula (Na,Ca,K,Ba,Sr)1-x(Mn,Mg,Al)6O12·3-4H2O. It was named in 1934 for the type locality, the Todoroki mine, Hokkaido, Japan. It belongs to the prismatic class 2/m of the monoclinic crystal system, but the angle β between the a and c axes is close to 90°, making it seem orthorhombic. It is a brown to black mineral which occurs in massive or tuberose forms.
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Because of unavailability of sufficiently large single crystals, little is known about the atomic structure of athabascaite. Copper (Cu+) serves as the cations, selenium (Se2−) serves as the anions, and the two are joined by ionic bonds. The crystal symmetry appears orthorhombic with the lattice parameters a = 8.227 ± 0.01, b = 11.982 ± 0.02, and c = 6.441 ± 0.01 Å. It has a calculated density of 6.59 g/cm3; this density is identical to that of umangite, and therefore the two are thought to have similar structure.
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Thallium(I) fluoride (or thallous fluoride or thallium monofluoride) is the chemical compound composed of thallium and fluorine with the formula TlF. It consists of hard white orthorhombic crystals which are slightly deliquescent in humid air but revert to the anhydrous form in dry air. It has a distorted sodium chloride (rock salt) crystal structure, due to the 6s2 inert pair on Tl+. Thallium(I) fluoride is unusual among the thallium(I) halides in that it is very soluble in water, while the others are not.
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TNAZ forms pale yellow crystals with a melting point of 101 °C. The compound crystallizes in an orthorhombic lattice with the space group Pbca. Thermolysis occurs starting around 240 °C - 250 °C with decomposition products that include nitrogen dioxide, nitric oxide, nitrous acid, carbon dioxide and formaldehyde. As far as energetic properties, it is roughly 30% more energetic than TNT and has a heat of explosion of ~6343 kJ/kg, a detonation velocity of ~9000 m/s, and a detonation pressure of 36.4 GPa.
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The one-dimensional conductivity is based on the bonding conditions in the S-N chain, where each sulfur atom provides two π electrons and each nitrogen atom provides one π electron to form two-center 3π electron bonding units. Two polymorphic crystal forms were observed in the compound. The monoclinic form I obtained from the synthesis can be converted into an orthorhombic form II by mechanical treatment such as grinding.Baughman, R.H.; Apgar, P.A.; Chance, R.R.; MacDiarmid, A.G.; Garito, A.F.: A New Phase of (SN)x in J. Chem. Soc. Chem. Comm.
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However, Below 110 K, ferrocene crystallizes in an orthorhombic crystal lattice in which the Cp rings are ordered and eclipsed, so that the molecule has symmetry group D5h. In the gas phase, electron diffraction and computational studies show that the Cp rings are eclipsed. The Cp rings rotate with a low barrier about the Cp(centroid)–Fe–Cp(centroid) axis, as observed by measurements on substituted derivatives of ferrocene using 1H and 13C nuclear magnetic resonance spectroscopy. For example, methylferrocene (CH3C5H4FeC5H5) exhibits a singlet for the C5H5 ring.
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Descloizite is a rare mineral species consisting of basic lead and zinc vanadate, , crystallizing in the orthorhombic crystal system and isomorphous with olivenite. Appreciable gallium and germanium may also be incorporated into the crystal structure. The color is deep cherry-red to brown or black, and the crystals are transparent or translucent with a greasy lustre; the streak is orange-yellow to brown; specific gravity 5.9 to 6.2; hardness 31/2. A variety known as cuprodescloizite is dull green in color; it contains a considerable amount of copper replacing zinc and some arsenic replacing vanadium.
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Fluorine has two solid forms, α- and β-fluorine. The latter crystallizes at −220 °C (−364 °F) and is transparent and soft, with the same disordered cubic structure of freshly crystallized solid oxygen, unlike the orthorhombic systems of other solid halogens. Further cooling to −228 °C (−378 °F) induces a phase transition into opaque and hard α-fluorine, which has a monoclinic structure with dense, angled layers of molecules. The transition from β- to α-fluorine is more exothermic than the condensation of fluorine, and can be violent..
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Feroxyhyte and lepidocrocite are both polymorphs of the iron oxyhydroxide FeO(OH) which are stable at the pressure and temperature conditions of the Earth's surface. Although they have the same chemical formula as goethite, their different crystalline structures make them distinct minerals. Additionally, goethite has several high-pressure and high-temperature polymorphs, which may be relevant to the conditions of the Earth's interior. These include ε-FeOOH, which has an orthorhombic crystal structure, a cubic pyrite-type polymorph with or without losing hydrogen and an ultradense hexagonal structure.
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Fayalite (Fe2SiO4; commonly abbreviated to Fa) is the iron-rich end-member of the olivine solid-solution series. In common with all minerals in the olivine group, fayalite crystallizes in the orthorhombic system (space group Pbnm) with cell parameters a 4.82 Å, b 10.48 Å and c 6.09 Å. Fayalite forms solid solution series with the magnesium olivine endmember forsterite (Mg2SiO4) and also with the manganese rich olivine endmember tephroite (Mn2SiO4). The atomic scale structure of fayalite looking along the A axis. Oxygen is shown in red, silicon in pink, and iron in blue.
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Other dihalides are received upon heating lead(II) salts with the halides of other metals; lead dihalides precipitate to give white orthorhombic crystals (diiodide form yellow hexagonal crystals). They can also be obtained by direct elements reaction at temperature exceeding melting points of dihalides. Their solubility increases with temperature; adding more halides first decreases the solubility, but then increases due to complexation, with the maximum coordination number being 6. The complexation depends on halide ion numbers, atomic number of the alkali metal, the halide of which is added, temperature and solution ionic strength.
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The material forms when Sb2O3 is heated in air:Holleman, A. F.; Wiberg, E. "Inorganic Chemistry" Academic Press: San Diego, 2001. . :Sb2O3 \+ 0.5 O2 → Sb2O4 ΔH = −187 kJ/mol At 800 °C, antimony(V) oxide loses oxygen to give the same material: :Sb2O5 → Sb2O4 \+ 0.5 O2 ΔH = −64 kJ/mol The material is mixed valence, containing both Sb(V) and Sb(III) centers. Two polymorphs are known, one orthorhombic (shown in the infobox) and one monoclinic. Both forms feature octahedral Sb(V) centers arranged in sheets with distorted Sb(III) centers bound to four oxides.
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BeH2 is usually formed as an amorphous white solid, but a hexagonal crystalline form with a higher density (~0.78 g cm−3) was reported, prepared by heating amorphous BeH2 under pressure, with 0.5-2.5% LiH as a catalyst. A more recent investigation found that crystalline beryllium hydride has a body-centred orthorhombic unit cell, containing a network of corner-sharing BeH4 tetrahedra, in contrast to the flat, hydrogen- bridged, infinite chains previously thought to exist in crystalline BeH2. Studies of the amorphous form also find that it consists of a network of corner shared tetrahedra.
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Waterhouseite, Mn7(PO4)2(OH)8, is a hydroxy manganese phosphate mineral. It is a medium-soft, brittle mineral occurring in pseudo-orthorhombic monoclinic bladed crystals and orange-brown to dark brown in color. Waterhouseite is on the softer side with a Mohs hardness of 4, has a specific gravity of 3.5 and a yellowish-brown streak. It is named after Frederick George Waterhouse, first director of the South Australian Museum, as well as recognizes the work Waterhouse Club has done in support of the South Australian Museum.
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Na3B3O3F6 contains isolated rings. K3B3O3F6 is monoclinic, space group P21/n, a=9.76 b=6.931 c=11.86 β=91.78 Z=12 volume=802 Å3 density=2.582. Melts at 432°C. Li2B3O4F3 is an ionic conductor due to its large channels. It contains linear chains of B3O4F3 rings. Its crystal structure is orthorhombic with space group P212121. Unit cell a=4.891, b=8.734, and c=12.301 Å. The subunit is a boroxine ring with tetrahedra BO2F2 and BO3F and a BO3 triangle. Cs3B3O3F6 can be produced by heating CsBF4, CsF, and H3BO3 together at 300°C.
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NH4B4O6F, (ABF) RbB4O6F (RBF), CsB4O6F, (CBF) For the rubidium and ammonium compounds the structure is orthorhombic. It contains borate sheets with fluorine pointing up and down into the between layers that contains the cations NH4, Rb or Cs. The units in the sheet are a BO3 triangle joined to a boroxine ring with an extra fluorine (B3O6F). Two oxygen atoms from the ring, and two from the triangle share with the adjacent units. The ammonium salt is stable to 300 °C, rubidium to 453 °C, and caesium to 609 °C.
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LiB6O9F contains a unit with two boroxine rings linked with a shared oxygen. One ring has an extra fluorine, and each connects to two other units through shared oxygen. Crystal structure orthorhombic space group Pna21, a = 7.6555 Å, b = 8.5318 Å, c = 10.7894 Å, Z = 4 Li2B6O9F2 has a three dimensional network which is composed of units with fused boroxine ring pairs connected to a BF2O2 bridge. monoclinic space group Cc formula weight 260.74 a = 4.821 b = 16.149 c = 10.057 β = 92.003 V=782.5 Z=4 density=2.213.
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There are two forms of Cu2S: a low temperature monoclinic form ("low-chalcocite") which has a complex structure with 96 copper atoms in the unit cell and a hexagonal form stable above 104 °C.Wells A.F. (1984) Structural Inorganic Chemistry, 5th ed., Oxford Science Publications, In this structure there are 24 crystallographically distinct Cu atoms and the structure has been described as approximating to a hexagonal close packed array of sulfur atoms with Cu atoms in planar 3 coordination. This structure was initially assigned an orthorhombic cell due to the twinning of the sample crystal.
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Orthorhombic MoTe2 has a resistance about 10% lower than the β form, and the resistance shows hysteresis of several degrees across the transition point around 250 K. The resistance drops roughly linearly with decreasing temperature. At 180 K resistivity is 2.52×10−4 Ω·cm, and at 120 mK the material becomes a superconductor. At low electric current levels the voltage is proportional to the current in the α form. With high electric currents MoTe2 shows negative resistance, where as the current increases the voltage across the material decreases.
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Above 69 GPa ε-N2 transforms to an orthorhombic phase designated by ζ-N2 with a 6% reduction in volume. The space group of ζ-N2 is P2221. The lattice constants are a=4.159 Å, b=2.765 Å, c=5.039 Å with eight atoms per unit cell. At 80 GPa the distance between nitrogen atoms in the molecules is 0.982 Å, but the closest distance to other nitrogen atoms is 1.93 Å. As the pressure increases to 138 GPa the bond in the molecules actually lengthens to 1.002 Å while intermolecular distances shorten.
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When compressing nitrogen to pressures between 120 and 180 GPa and temperatures above 4000 °C, it adopts a crystal structure identical to that of black phosphorus (orthorhombic, Cmce space group), hence coined as black phosphorus nitrogen (bp-N) or simply black nitrogen. Like black phosphorus, it is an electrical conductor. The formation of the bp-N structure brings nitrogen in line with heavier pnictogen elements, and reaffirms the trend that elements at high pressure adopt the same structures as the same-group elements below them in the periodic table at lower pressures.
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The atoms in each grain are organized into one of seven 3d stacking arrangements or crystal lattices (cubic, tetrahedral, hexagonal, monoclinic, triclinic, rhombohedral and orthorhombic). The direction of alignment of the matrices differ between adjacent crystals, leading to variance in the reflectivity of each presented face of the interlocked grains on the galvanized surface. The average grain size can be controlled by processing conditions and composition, and most alloys consist of much smaller grains not visible to the naked eye. This is to increase the strength of the material (see Hall-Petch Strengthening).
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It is also called "modification III" of the metaboric acids. Upon heating at 130-140 °C in a sealed ampoule (to prevent dehydration), orthorhombic metaboric acid converts to the monoclinic form: :(BOH)3O3 → B3O4(OH)(H2O) This material, called modification II, has a polymeric structure, and a higher melting point (201 °C) and density (2.045 g/cm3). The structure of this species resembles its precursor except that the rings are connected and 1/3 of the boron centres are tetrahedral.W. H. Zachariasen "The crystal structure of monoclinic metaboric acid" Acta Crystallogr.
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Crystals with an inversion center cannot display certain properties, such as the piezoelectric effect. The following space groups have inversion symmetry: the triclinic space group 2, the monoclinic 10-15, the orthorhombic 47-74, the tetragonal 83-88 and 123-142, the trigonal 147, 148 and 162-167, the hexagonal 175, 176 and 191-194, the cubic 200-206 and 221-230. Point groups lacking an inversion center (non-centrosymmetric) can be polar, chiral, both, or neither. A polar point group is one whose symmetry operations leave more than one common point unmoved.
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An experiment conducted by Josiah Wedgwood, led to it being used in his 'Jasper ware'; the mineral had previously been considered as worthless. Witherite has been used for hardening steel, and for making cement, glass, enamelware, soap, dye and explosives.'Looking Back' p10 Hexham Courant 10 January 2014 featuring a photograph of Settlingstones miners in 1905 Witherite crystallizes in the orthorhombic system. The crystals are invariably twinned together in groups of three, giving rise to pseudo-hexagonal forms somewhat resembling bipyramidal crystals of quartz, the faces are usually rough and striated horizontally.
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The setting of plaster of Paris is accompanied by a slight expansion of volume due to which it is used in making casts for statue, toys, etc. The initial matrix consists mostly of orthorhombic crystals - the kinetic product. Over the next 72 hours the rhombic crystals give way to an interlocking mass of monoclinic crystal needles and the plaster increases in hardness and gains strength. If plaster or gypsum is heated above 130 °C, (266 °F) , hemihydrate is formed, which will also re-form as gypsum if mixed with water.
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The overall methodology is similar to the use of AgPF6, except that Tl+ is much less oxidizing. The crystalline structure is of cubic caesium chloride type at room temperature, but it lowers to the orthorhombic thallium iodide type upon cooling, the transition temperature being likely affected by the impurities. Nanometer-thin TlCl films grown on KBr substrates exhibit a rocksalt structure, while the films deposited on mica or NaCl are of the regular CsCl type. A very rare mineral lafossaite, Tl(Cl,Br), is a natural form of thallium(I) chloride.Lafossaite. Mindat.
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The Lovozero Massif is an area with an igneous mountain range, home to various types of minerals such as eudialyte, loparite, and natrosilitite. Crystallographically, zorite belongs in the orthorhombic group, which has 3 axes, a, b, and c that are of unequal lengths (a≠b≠c) that form 90° with each other. It also belongs in the point group 2/m2/m2/m. The state of aggregation for zorite is acicular. Zorite has perfect cleavage along the planes {010} and {001}, while having poor cleavage along the plane {110}.Fleischer, M. (1973) New Mineral Names.
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Topaz is a silicate mineral of aluminium and fluorine with the chemical formula Al2SiO4(F, OH)2. Topaz crystallizes in the orthorhombic system, and its crystals are mostly prismatic terminated by pyramidal and other faces. It is one of the hardest naturally occurring minerals (Mohs hardness of 8) and is the hardest of any silicate mineral. This hardness combined with its usual transparency and variety of colors means that it has acquired wide use in jewellery as a cut gemstone as well as for intaglios and other gemstone carvings.
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Rhodium hexafluoride is prepared by reaction of rhodium metal with an excess of elemental fluorine: :Rh + 3 F2 → RhF6 The RhF6 molecule has octahedral molecular geometry. Consistent with its d3 configuration, the six Rh–F bond lengths are equivalent, being 1.824 Å. It crystallises in an orthorhombic space group Pnma with lattice parameters of a = 9.323 Å, b = 8.474 Å, and c = 4.910 Å. Like some other metal fluorides, RhF6 is highly oxidizing. It attacks even glass even in the absence of water. It can even react with elemental oxygen.
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In the orthorhombic system, crystals usually twin on planes parallel to the prism face, where the most common is a {110} twin which produces cyclical twins, such as in aragonite, chrysoberyl, and cerussite. In the monoclinic system, twin occur most often on the planes {100} and {001} by the Manebach Law {001}, Carlsbad Law [001], Braveno Law {021} in orthoclase, and the Swallow Tail Twins {001} in gypsum. In the triclinic system, the most commonly twinned crystals are the feldspar minerals plagioclase and microcline. These minerals show the Albite and Pericline Laws.
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MIEC materials tend to be nonstoichiometric oxides, many of which have perovskite structures with rare earth metals on the A-site and transition metals on the B-site. Substituting various ions into the lattice of such an oxide can result in increased electronic conductivity through the formation of holes and introduce ionic conductivity by developing oxygen vacancies. This mechanism is known as defect theory, which states that defects like these offer additional pathways that favor fast diffusion. Other promising materials include those with pyrochlore, brownmillerite, Ruddlesden- Popper, and orthorhombic K2NiF4-type structures.
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Pyroxenes that crystallize in the monoclinic system are known as clinopyroxenes and those that crystallize in the orthorhombic system are known as orthopyroxenes. The name pyroxene is derived from the Ancient Greek words for fire (πυρ) and stranger (ξένος). Pyroxenes were so named because of their presence in volcanic lavas, where they are sometimes seen as crystals embedded in volcanic glass; it was assumed they were impurities in the glass, hence the name "fire strangers". However, they are simply early-forming minerals that crystallized before the lava erupted.
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For example, the biotite series is represented by variable amounts of the endmembers phlogopite, siderophyllite, annite, and eastonite. In contrast, a mineral group is a grouping of mineral species with some common chemical properties that share a crystal structure. The pyroxene group has a common formula of XY(Si,Al)2O6, where X and Y are both cations, with X typically bigger than Y; the pyroxenes are single-chain silicates that crystallize in either the orthorhombic or monoclinic crystal systems. Finally, a mineral variety is a specific type of mineral species that differs by some physical characteristic, such as colour or crystal habit.
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Cupalite forms dendritic, rounded or irregular grains, typically below 0.1 millimeter in size, which are intergrown with khatyrkite. They have an orthorhombic crystal structure with a yet uncertain space group and the lattice constants a = 0.695(1) nm, b = 0.416(1) nm, c = 1.004(1) nm, and 10 formula units per unit cell. Their Mohs hardness is between 4 and 4.5 and Vickers hardness is in the range 272–318 kg/mm2 for a 20–50 gram load. Cupalite and khatyrkite are accompanied by spinel, corundum, stishovite, augite, forsteritic olivine, diopsidic clinopyroxene and several Al-Cu-Fe metal alloy minerals.
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Monoclinic crystals (and triclinic and orthorhombic crystals) have two directions in which light travels with zero birefringence; these directions are called the optic axes, and the crystal is said to be biaxial. The speed of a ray of light travelling through the crystal differs with direction. The direction of the fastest ray is called the X direction and the direction of the slowest ray is called the Z direction. X and Z are perpendicular to each other, and a third direction Y is defined as perpendicular to both X and Z; light travelling along Y has an intermediate speed.
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It forms alloys with lanthanide metals but little is known about the resulting materials. The element has two crystalline forms at standard atmospheric pressure: a double-hexagonal close-packed form dubbed alpha (α) and a face-centered cubic form designated beta (β). The α form exists below 600–800 °C with a density of 15.10 g/cm3 and the β form exists above 600–800 °C with a density of 8.74 g/cm3. At 48 GPa of pressure the β form changes into an orthorhombic crystal system due to delocalization of the atom's 5f electrons, which frees them to bond.
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Travertine terraces in Pamukkale, Turkey At 3%, calcium is the fifth most abundant element in the Earth's crust, and the third most abundant metal behind aluminium and iron. It is also the fourth most abundant element in the lunar highlands. Sedimentary calcium carbonate deposits pervade the Earth's surface as fossilized remains of past marine life; they occur in two forms, the rhombohedral calcite (more common) and the orthorhombic aragonite (forming in more temperate seas). Minerals of the first type include limestone, dolomite, marble, chalk, and iceland spar; aragonite beds make up the Bahamas, the Florida Keys, and the Red Sea basins.
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A more complex example is in The Chemistry of Metal Alkoxides, published by Kluwer Academic Publishers, year 2002, section 9.4 on lead alkoxides, page 115. especially in the glass industry, which is the biggest user of PbO. The definition of massicot as orthorhombic PbO dates from the 1840s, but the substance massicot and the name massicot has been in use since the late medieval era.Some comments about the evolution of the definition of the word massicot over the past few centuries is in Lead Manufacturing in Britain: A History, by David John Rowe, year 1983, page 16.
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Orthorhombic crystals (and monoclinic and triclinic crystals) have two directions in which light travels with zero birefringence; these directions are called the optic axes, and the crystal is said to be biaxial. The speed of a ray of light travelling through the crystal differs with direction. The direction of the fastest ray is called the X direction and the direction of the slowest ray is called the Z direction. X and Z are perpendicular to each other and a third direction Y is defined as perpendicular to both X and Z; light travelling along Y has an intermediate speed.
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They are isostructural and all have orthorhombic crystal structure and occur in lunar and terrestrial rocks.Ferropseudobrookite, Mindat Chemical composition of most armalcolite samples can be decomposed into a sum of metal oxides as follows: TiO2 (concentration 71–76%), FeO (10–17%), MgO (5.5–9.4%), Al2O3 (1.48-2%), Cr2O3 (0.3-2%) and MnO (0-0.83%). Whereas the titanium content is relatively constant, the ratio of magnesium to iron varies and is usually lower than 1. A so-called Cr-Zr-Ca variety of armacolite is distinguished which has an elevated content of Cr2O3 (4.3–11.5%), ZrO2 (3.8–6.2%) and CaO (3-3.5%).
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Sodium metaperiodate (NaIO4) forms tetragonal crystals (space group I41/a) consisting of slightly distorted ions with average I–O bond distances of 1.775 Å; the Na+ ions are surrounded by 8 oxygen atoms at distances of 2.54 and 2.60 Å. Sodium hydrogen periodate (Na2H3IO6) forms orthorhombic crystals (space group Pnnm). Iodine and sodium atoms are both surrounded by an octahedral arrangement of 6 oxygen atoms; however the NaO6 octahedron is strongly distorted. IO6 and NaO6 groups are linked via common vertices and edges. Powder diffraction indicates that Na5IO6 crystallises in the monoclinic system (space group C2/m).
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In this framework, the neighboring supericosahedra are rotated 90° with respect to each other. On the contrary, in Sc4.5–xB57–y+zC3.5–z the supericosahedra form a 2-dimensional network where the 90° rotation relation is broken because of the orthorhombic symmetry. The planar projections of the supericosahedron connection in Sc4.5–xB57–y+zC3.5–z and YB66 are shown in figures 27a and b, respectively. In the YB66 crystal structure, the neighboring 2-dimensional supericosahedron connections are out-of-phase for the rotational relation of the supericosahedron. This allows 3-dimensional stacking of the 2-dimensional supericosahedron connection while maintaining the cubic symmetry.
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The absorption spectrum of astatine in the middle ultraviolet region has lines at 224.401 and 216.225 nm, suggestive of 6p to 7s transitions. The structure of solid astatine is unknown. As an analogue of iodine it may have an orthorhombic crystalline structure composed of diatomic astatine molecules, and be a semiconductor (with a band gap of 0.7 eV). Alternatively, if condensed astatine forms a metallic phase, as has been predicted, it may have a monatomic face-centered cubic structure; in this structure it may well be a superconductor, like the similar high-pressure phase of iodine.
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The crystal system of post-perovskite is orthorhombic, its space group is Cmcm, and its structure is a stacked SiO6-octahedral sheet along the b axis. The name "post-perovskite" derives from silicate perovskite, the stable phase of MgSiO3 throughout most of Earth's mantle, which has the perovskite structure. The prefix "post-" refers to the fact that it occurs after perovskite structured MgSiO3 as pressure increases (and historically, the progression of high pressure mineral physics). At upper mantle pressures, nearest Earth's surface, MgSiO3 persists as the silicate mineral enstatite, a pyroxene rock forming mineral found in igneous and metamorphic rocks of the crust.
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A proposal of studying vortices with half magnetic flux quanta in heavy-fermion superconductors in three polycrystalline configurations was reported in 1987 by V. B. Geshkenbein, A. Larkin and A. Barone in 1987. In the first tricrystal pairing symmetry experiment , the spontaneous magnetization of half flux quantum was clearly observed in YBCO, which convincingly supported the d-wave symmetry of the order parameter in YBCO. Because YBCO is orthorhombic, it might inherently have an admixture of s-wave symmetry. So, by tuning their technique further, it was found that there was an admixture of s-wave symmetry in YBCO within about 3%.
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Olivenite is a copper arsenate mineral, formula Cu2AsO4OH. It crystallizes in the monoclinic system (pseudo-orthorhombic), and is sometimes found in small brilliant crystals of simple prismatic habit terminated by domal faces. More commonly, it occurs as globular aggregates of acicular crystals, these fibrous forms often having a velvety luster; sometimes it is lamellar in structure, or soft and earthy. A characteristic feature, and one to which the name alludes (German, Olivenerz, of A. G. Werner, 1789), is the olive-green color, which varies in shade from blackish-green in the crystals to almost white in the finely fibrous variety known as woodcopper.
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Orthorhombic orange-yellow crystals of a 1:1 mixture of picryl chloride and hexamethylbenzene have been reported to possess alternating stacks of each component, probably due to π-stacking of the aromatic systems. It is insoluble in water, but soluble in organic solvents including benzene and ethanol. Hexamethylbenzene is sometimes called mellitene, a name derived from mellite, a rare honey-coloured mineral; meli (GEN melitos) is the Greek word for honey.. Mellite is composed of a hydrated aluminium salt of benzenehexacarboxylic acid (mellitic acid), with formula . Mellitic acid itself can be derived from the mineral, and subsequent reduction yields mellitene.
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But, even if the junction experiment is the strongest method to determine the symmetry of the HTS order parameter, the results have been ambiguous. J. R. Kirtley and C. C. Tsuei thought that the ambiguous results came from the defects inside the HTS, so that they designed an experiment where both clean limit (no defects) and dirty limit (maximal defects) were considered simultaneously. In the experiment, the spontaneous magnetization was clearly observed in YBCO, which supported the d symmetry of the order parameter in YBCO. But, since YBCO is orthorhombic, it might inherently have an admixture of s symmetry.
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Mottramite is an orthorhombic mineral belonging to the crystal class 2/m 2/m 2/m, with space group Pnma. The unit cell has sides of lengths a = 7.6 to 7.7 Å, b = 9.2 to 9.5 Å and c = 6.0 to 6.1 Å.Van der Westhuizen, de Bruiyn, Tordiffe and Botha (1986). The descloizite-mottramite series of vanadates from the Otavi Mountain Land, South West Africa: an X-ray study. Mineralogical Magazine 50:137 There are four formula units per unit cell (Z = 4), the molar mass is 402.69 g and the calculated density is 6.19 g/cm3.
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Orthorhombic crystals (and triclinic and monoclinic crystals) have two directions in which light travels with zero birefringence; these directions are called the optic axes, and the crystal is said to be biaxial. The speed of a ray of light travelling through the crystal differs with direction. The direction of the fastest ray is called the X direction and the direction of the slowest ray is called the Z direction. X and Z are perpendicular to each other, and a third direction Y is defined as perpendicular to both X and Z; light travelling along Y has an intermediate speed.
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Wadsleyite, a high-pressure phase of olivine, is an orthorhombic mineral with the formula β-(Mg,Fe)2SiO4.It was first found in nature in the Peace River meteorite from Alberta, Canada. It is formed by a phase transformation from olivine (α-(Mg,Fe)2SiO4) under increasing pressure and eventually transforms into spinel-structured ringwoodite (γ-(Mg,Fe)2SiO4) as pressure increases further. The structure can take up a limited amount of other bivalent cations instead of magnesium, but contrary to the α and γ structures, a β structure with the sum formula Fe2SiO4 is not thermodynamically stable.
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Berkelium forms a trigonal (η5–C5H5)3Bk complex with three cyclopentadienyl rings, which can be synthesized by reacting berkelium(III) chloride with the molten beryllocene Be(C5H5)2 at about 70 °C. It has an amber color and orthorhombic symmetry, with the lattice constants of a = 1411 pm, b = 1755 pm and c = 963 pm and the calculated density of 2.47 g/cm3. The complex is stable to heating to at least 250 °C, and sublimates without melting at about 350 °C. The high radioactivity of berkelium gradually destroys the compound within a period of weeks.
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Above the pressure of 10.5 GPa magnetoresistance disappears and the material becomes a superconductor. At 13.0 GPa the transition to superconductivity happens below 6.5 K. WTe2 was predicted to be a Weyl semimetal and, in particular, to be the first example of a Type II Weyl semimetal, where the Weyl nodes exist at the intersection of the electron and hole pockets. It has also been reported that terahertz- frequency light pulses can switch the crystal structure of WTe2 between orthorhombic and monoclinic by altering the material’s atomic lattice. Tungsten ditelluride can be exfoliated into thin sheets down to single layers.
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The structure of eveslogite is based upon complex rods that consist of the corner sharing octahedral (TiO) and the tetrahedral SiO4. Due to its 5- Apatite hardness and density of 2.85 the general structure of this mineral is a rigid but porous in nature just like other astrophyllite. Some of the minerals that are largely associated with Eveslogite in terms of close similarity of their structure include nepheline, biotite, fluorite, K-feldspar, eudialyte and also many other minerals that fall under the astrophyllite group. Eveslogite is an orthorhombic mineral that fits within the space group 2lm prismatic.
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It is monoclinic m with space group Cc, but crystals are pseudotetragonal. Scolecite, like natrolite and mesolite, usually occurs as acicular (needle-like) and fibrous aggregations. It has nearly the same angles between the crystal faces as does natrolite, but natrolite is orthorhombic and scolecite is monoclinic. The etched figures (figures that arise from the action of a solvent on a crystal face, and indicate its true symmetry) and the pyroelectric character of scolecite show that it crystallizes with a plane of symmetry, but no axis of symmetry, that is to say it belongs to the hemihedral class of the monoclinic system.
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Due to these properties, among others, CrB has been considered as a candidate material for wear resistant coatings and high-temperature diffusion barriers. It can be synthesized as powders by many methods including direct reaction of the constituent elemental powders, self-propagating high-temperature synthesis (SHS), borothermic reduction, and molten salt growth. Slow-cooling of molten aluminum solutions from high-temperatures has been used to grow large single crystals, with a maximum size of 0.6 mm x 0.6 mm x 8.3 mm. CrB has an orthorhombic crystal structure (space group Cmcm) that was first discovered in 1951, and subsequently confirmed by later work using single crystals.
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Bronzite variety from the Bare Hills copper mine, Baltimore County, Maryland, USA (size: 9.6 x 7.5 x 4.9 cm) Bronzitite, thin section of a rock made of olivine and pyroxene, mostly bronzite. Photomicrograph, viewed with polarized light. Bronzite is a member of the pyroxene group of minerals, belonging with enstatite and hypersthene to the orthorhombic series of the group. Rather than a distinct species, it is really a ferriferous variety of enstatite, which owing to partial alteration has acquired a bronze-like sub-metallic luster on the cleavage surfaces. Enstatite is magnesium silicate, MgSiO3, with the magnesium partly replaced by small amounts (up to about 12%) of Fe+2.
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Diaspore , also known as diasporite, empholite, kayserite, or tanatarite, is an aluminium oxide hydroxide mineral, α-AlO(OH), crystallizing in the orthorhombic system and isomorphous with goethite. It occurs sometimes as flattened crystals, but usually as lamellar or scaly masses, the flattened surface being a direction of perfect cleavage on which the lustre is markedly pearly in character. It is colorless or greyish-white, yellowish, sometimes violet in color, and varies from translucent to transparent. It may be readily distinguished from other colorless transparent minerals with a perfect cleavage and pearly luster—like mica, talc, brucite, and gypsum— by its greater hardness of 6.5 - 7.
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Those that have three phase transitions go through these crystallographic point groups: P213 – P21 – P1 – P212121, whereas the single phase change crystals only have P213 – P212121. K2Cd2(SO4)3 has a transition temperature above room temperature, so that it is ferroelectric in standard conditions. The orthorhombic cell size is a=10.2082 Å, b=10.2837 Å, c=10.1661 Å. Where the crystals change phase there is a discontinuity in the heat capacity. The transitions may show thermal hysteresis. Different cations can be substituted so that for example K2Cd2(SO4)3 and Tl2Cd2(SO4)3 can form solid solutions for all ratios of thallium and potassium.
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The crystal structure of PtSi is orthorhombic, with each silicon atom having six neighboring platinum atoms. The distances between the silicon and the platinum neighbors are as follows: one at a distance of 2.41 angstroms, two at a distance of 2.43 angstroms, one at a distance of 2.52 angstroms, and the final two at a distance of 2.64 angstroms. Each platinum atom has six silicon neighbors at the same distances, as well as two platinum neighbors, at a distance of 2.87 and 2.90 angstroms. All of the distances over 2.50 angstroms are considered too far to really be involved in bonding interactions of the compound.
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The 122s form in the I4/mmm tetragonal structure. For example, the tetragonal unit cell of SrFe2As2, at room temperature, has lattice parameters a = b = 3.9243 Å and c = 12.3644 Å. The planar geometry is reminiscent of the cuprate high-Tc superconductors in which the Cu-O layers are believed to support superconductivity. These materials undergo a first- order structural phase transition into the Fmmm orthorhombic structure below some characteristic temperature T0 that is compound specific. NMR experiments on the CaFe2As2 show that there is a first-order antiferromagnetic magnetic phase transition at the same temperature; in contrast, the antiferromagnetic transition occurs at a lower temperature in the 1111s.
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Leucite is a rock-forming mineral of the feldspathoid group, silica- undersaturated and composed of potassium and aluminium tectosilicate KAlSi2O6. Crystals have the form of cubic icositetrahedra but, as first observed by Sir David Brewster in 1821, they are not optically isotropic, and are therefore pseudo-cubic. Goniometric measurements made by Gerhard vom Rath in 1873 led him to refer the crystals to the tetragonal system. Optical investigations have since proved the crystals to be still more complex in character, and to consist of several orthorhombic or monoclinic individuals, which are optically biaxial and repeatedly twinned, giving rise to twin-lamellae and to striations on the faces.
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Lawsonite has crystal habits of orthorhombic prismatic, which are crystals shaped like slender prisms, or tubular figures, which are form dimensions that are thin in one direction, both with two perfect cleavages. This crystal is transparent to translucent and varies in color from white to pale blue to colorless with a white streak and a vitreous or greasy luster. It has a relatively low specific gravity of 3.1g/cm3, and a pretty high hardness of 7.5 on Mohs scale of hardness, slightly higher than quartz. Under the microscope, lawsonite can be seen as blue, yellow, or colorless under plane polarized light while the stage is rotated.
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TaN is often prepared as thin films. Methods of depositing the films include RF-magnetron-reactive sputtering, Direct current (DC) sputtering, Self-propagating high-temperature synthesis (SHS) via 'combustion' of Tantalum powder in Nitrogen, low‐pressure metalorganic chemical vapor deposition (LP‐MOCVD), ion beam assisted deposition (IBAD), and by electron beam evaporation of tantalum in concert with high energy nitrogen ions. Depending on the relative amount of N2, the deposited film can vary from (fcc) TaN to (hexagonal) Ta2N as nitrogen decreases. A variety of other phases have also been reported from deposition including bcc and hexagonal TaN; hexagonal Ta5N6; tetragonal Ta4N5; orthorhombic Ta6N2.5, Ta4N, or Ta3N5.
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Todorokite is biaxial, as are all monoclinic (and orthorhombic) minerals. In the polariscope,Polariscope, Gemstone Buzz and in the polarizing microscope, specimens may be illuminated from below by light that is polarized by the polarizer, and viewed from above through an analyzer that transmits light of only one direction of polarization. When the directions of polarization of the polarizer and analyzer are at right angles, the specimen is said to be viewed between crossed polars. When todorokite is rotated between crossed polars it appears dark and light in turn, being dark when the crystal face or cleavage face is parallel to one direction of polarization.
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Lattice parameters are a = 6.16 Å. There are two formula units (in this case, discrete molecules) per unit cell, giving a density of 3.02 g·cm−3. Below this temperature (measured at −19 °C), the solid structure is orthorhombic space group Pnma. Lattice parameters are a = 9.55 Å, b = 8.74 Å, and c = 5.02 Å. There are four formula units (in this case, discrete molecules) per unit cell, giving a density of 3.38 g·cm−3. At −140 °C, the solid structure is still orthothombic, but the lattice parameters are now a = 9.360 Å, b = 8.517 Å, and c = 4.934 Å, giving a density of 3.58 g·cm−3.
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The higher-temperature γ-phase also changes into ε-iron, but does so at higher pressure. Some controversial experimental evidence exists for a stable β phase at pressures above 50 GPa and temperatures of at least 1500 K. It is supposed to have an orthorhombic or a double hcp structure. (Confusingly, the term "β-iron" is sometimes also used to refer to α-iron above its Curie point, when it changes from being ferromagnetic to paramagnetic, even though its crystal structure has not changed.) The inner core of the Earth is generally presumed to consist of an iron-nickel alloy with ε (or β) structure.
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Cs, which yields a Goldschmidt tolerance factor of less than one, results in a distorted, orthorhombic structure at room temperature. This results in reduced orbital overlap between the halide and lead atoms and blue shifts the absorption and emission spectra. On the other hand, FA yields a cubic structure and results in FAPbX3 having red shifted absorption and emission spectra as compared to both Cs and MA. Of these three cations, MA is intermediate size between Cs and FA and therefore results in absorption and emission spectra intermediate between those of Cs and FA. Through the combination of both anionic and cationic tuning, the whole spectrum ranging from near-UV to near-IR can be covered.
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Nb2O5 is prepared by hydrolysis of alkali-metal niobates, alkoxides or fluoride using base. Such ostensibly simple procedures afford hydrated oxides that can then be calcined. Pure Nb2O5 can also be prepared by hydrolysis of NbCl5:Process for the manufacture of niobium pentoxide or tantalum pentoxide, Kern, Therwil, Jacob, Hooper (CIBA Switzerland), US Patent number: 3133788, (1964) :2 NbCl5 \+ 5 H2O → Nb2O5 \+ 10 HCl A method of production via sol-gel techniques has been reported hydrolysing niobium alkoxides in the presence of acetic acid, followed by calcination of the gels to produce the orthorhombic form, T-Nb2O5.Sol-gel route to niobium pentoxide, P Griesmar, G Papin, C Sanchez, J Livage - Chem. Mater.
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However, these reports have become controversial as reported in Nature because other groups have not been able to reproduce the reported bulk thermal conductivity data. SnSe performance metrics Although it exists at room temperature in an orthorhombic structure with space group Pnma, SnSe has been shown to undergo a transition to a structure with higher symmetry, space group Cmcm, at higher temperatures. This structure consists of Sn-Se planes that are stacked upwards in the a-direction, which accounts for the poor performance out-of-plane (along a-axis). Upon transitioning to the Cmcm structure, SnSe maintains its low thermal conductivity but exhibits higher carrier mobilities, leading to its excellent ZT value.
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The complex is prepared by reducing chloroauric acid with triphenylphosphine in 95% ethanol:Pierre Braunstein, Hans Lehner, Dominique Matt "A Platinum-Gold Cluster: Chloro-1κCl-Bis(Triethylphosphine-1κP)Bis(Triphenylphosphine)-2κP, 3κP-Triangulo- Digold-Platinum(1 +) Trifluoromethanesulfonate" Inorganic Syntheses, 1990, Volume 27, Pages 218–221. :HAuCl4 \+ H2O + 2 PPh3 → (Ph3P)AuCl + Ph3PO + 3 HCl Ph3PAuCl can also be prepared by treating a thioether complex of gold like (dimethyl sulfide)gold(I) chloride, [(Me2S)AuCl], with triphenylphosphine. The complex adopts a linear coordination geometry, which is typical of most gold(I) compounds. It crystallizes in the orthorhombic space group P212121 with a = 12.300(4) Å, b = 13.084(4) Å, c = 10.170(3) Å with Z = 4 formula units per unit cell.
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Wulffite is specific sulfate labeled under alkali copper sulfates with its empirical formula calculated from 18 Oxygen to be Nal.08(K2.85Rb0.08Cs0.04)Σ2.97(Cu3.99Zn0.02)Σ4.01S3.99O18. Wulffite has also been shown to dissolve in water showing that its bonds are weak enough to dissolve in room temperature water. Many forms of X-ray analysis were performed such as X-ray Powder Diffraction, Single Crystal Diffraction and Jeol JSM-6480LV a scanning electron microscope to find the chemical composition and crystal structure to compile the data of the new mineral. The analysis showed that Wulffite has an orthorhombic crystal system structure with a basic unit of a heteropolyhedral quasi-framework formed from Cu-O-S chains.
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Tin(II) selenide adopts a layered orthorhombic crystal structure at room temperature, which can be derived from a three- dimensional distortion of the NaCl structure. There are two-atom-thick SnSe slabs (along the b–c plane) with strong Sn–Se bonding within the plane of the slabs, which are then linked with weaker Sn–Se bonding along the a direction. The structure contains highly distorted SnSe7 coordination polyhedra, which have three short and four very long Sn–Se bonds, and a lone pair of the Sn2+ sterically accommodated between the four long Sn–Se bonds. The two-atom-thick SnSe slabs are corrugated, creating a zig-zag accordion-like projection along the b axis.
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Gedrite is a crystal belonging to the orthorhombic ferromagnesian subgroup of the amphibole supergroup of the double chain inosilicate minerals with the ideal formula: Mg2(Mg3Al2)(Si6Al2)O22(OH)2 Gedrite is the magnesium (Mg) rich endmember of a solid solution series, with divalent magnesium cations readily replaced with ferrous iron (Fe), leading to the iron rich endmember 'ferrogedrite', with the formula: Fe2+2(Fe2+3Al2)(Si6Al2)O22(OH)2. However, pure endmembers are very rare, with often either one of the mentioned cations dominating the composition. Thus, the formula can be written in such a way to express common intermediary gedrite samples: (Mg,Fe)2+2(Mg,Fe)2+3Al2(Al2Si6O22)(OH)2. Divalent manganese (Mn) may substitute for some of the magnesium.
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An orthoferrite is any of a class of chemical compounds with the formula RFeO, where R is one or more rare-earth elements. Orthoferrites have an orthorhombic crystal structure with a space group Pbnm and most are weakly ferromagnetic."orthoferrite", Oxford English Dictionary, Draft Revision March 2008 At the Néel temperature T_N the subsystem of iron ions orders into a slightly canted antiferromagnetic structure with antiferromagnetic moment G and a weak ferromagnetic moment F. The rare-earth ion subsystem acquires magnetization m due to an interaction with the iron subsystem. The orthoferrites are particularly interesting because of the presence of an antisymmetric exchange interaction which involves the vector cross product of neighboring spins as opposed to the usual scalar product.
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Synthetic scheelite produced via the Czochralski process is available, but it has never been widely used as a diamond simulant. Due to the scarcity of natural gem- quality scheelite, synthetic scheelite is much more likely to simulate it than diamond. A similar case is the orthorhombic carbonate cerussite, which is so fragile (very brittle with four directions of good cleavage) and soft (hardness 3.5) that it is never seen set in jewelry, and only occasionally seen in gem collections because it is so difficult to cut. Cerussite gems have an adamantine luster, high RI (1.804–2.078), and high dispersion (0.051), making them attractive and valued collector's pieces. Aside from softness, they are easily distinguished by cerussite's high density (SG 6.51) and anisotropy with extreme birefringence (0.271).
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Cross Section view of the structures that can be formed by phospholipids in aqueous solutions Polymorphism in biophysics is the ability of lipids to aggregate in a variety of ways, giving rise to structures of different shapes, known as "phases". This can be in the form of sphere of lipid molecules (micelles), pairs of layers that face one another (lamellar phase, observed in biological systems as a lipid bilayer), a tubular arrangement (hexagonal), or various cubic phases (Fdm, Imm, Iam, Pnm, and Pmm being those discovered so far). More complicated aggregations have also been observed, such as rhombohedral, tetragonal and orthorhombic phases. It forms an important part of current academic research in the fields of membrane biophysics (polymorphism), biochemistry (biological impact) and organic chemistry (synthesis).
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Though lawsonite and anorthite have similar compositions, their structures are quite different. While anorthite has a tetrahedral coordination with Al (Al substitutes for Si in feldspars), lawsonite has an octahedral coordination with Al, making it an orthorhombic sorosilicate with a space group of Cmcm which consists of Si2O7 Groups and O, OH, F, and H2O with cations in [4] and/or > [4] coordination. This is much similar to the epidote group which lawsonite is often found in conjunction with, which are also sorosilicates because their structure consists of two connected SiO4 tetrahedra plus connecting cation. The water contained in its structure is made possible by cavities formed by rings of two Al octahedral and two Si2O7 groups, each containing an isolated water molecule and calcium atom.
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Stellerite is part of the orthorhombic crystal system which means it has three axes of unequal length that intersect at 90° angles. Its crystal class is rhombic-dipyramidal which means it has three perpendicular two-fold rotational axes with perpendicular mirror planes.Miller,S.A., and Taylor, J.C. (1985) Neutron Single Crystal Diffraction Study of an Australian Stellerite Zeolites, 5, 7-10. This would look like a dipyramid cut horizontally along the middle to where the top and bottom halves each have four identical faces that can either be compared to the other faces by the 2-fold rotation axes or the mirror planes.. Accessed 2 December 2010 Stilbite, another zeolite, is very similar to stellerite in both chemical composition and physical appearance.
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Like solid chlorine and iodine, solid bromine crystallises in the orthorhombic crystal system, in a layered lattice of Br2 molecules. The Br–Br distance is 227 pm (close to the gaseous Br–Br distance of 228 pm) and the Br···Br distance between molecules is 331 pm within a layer and 399 pm between layers (compare the van der Waals radius of bromine, 195 pm). This structure means that bromine is a very poor conductor of electricity, with a conductivity of around 5 × 10−13 Ω−1 cm−1 just below the melting point, although this is better than the essentially undetectable conductivity of chlorine. At a pressure of 55 GPa (roughly 540,000 times atmospheric pressure) bromine undergoes an insulator-to-metal transition.
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Cooperative PJTE in BaTiO3-type crystals and ferroelectricity. In crystals with PJTE centers the interaction between the local distortions may lead to their ordering to produce a phase transition to a regular crystal phase with lower symmetry. Such cooperative PJTE is quite similar to the cooperative JTE; it was shown in one of the first studies of the PJTE in solid state systems that in the case of ABO3 crystals with perovskite structure the local dipolar PJTE distortions at the transition metal B center and their cooperative interactions lead to ferroelectric phase transitions. Provided the criterion for PJTE is met, each [BO6] center has an APES with eight equivalent minima along the trigonal axes, six orthorhombic, and (higher) twelve tetragonal saddle-points between them.
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Bates' research in polymer science focuses primarily on the self-assembly of block copolymers into ordered nanoscale morphologies, the dynamics of block copolymers and polymer blends, and the useful bulk physical properties of these materials. One of his most significant contributions in experimental polymer physics is a comprehensive understanding of the thermodynamically-driven microphase separation of diblock copolymers with quantitative comparisons to theories developed by Ludwik Leibler and others. This work has had impact on the design of commercial multiblock copolymers for widespread applications. Bates is also credited with supplying a detailed understanding of the formation of bicontinuous and tricontinuous network phase morphologies in block copolymers, including the conclusive identification of the double gyroid morphology in diblock copolymers and the discovery of the first two orthorhombic network phases in soft materials.
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Cu2SO4 crystallizes in the orthorhombic space group Fddd with cubic closest pack cell unit properties a = 474.8, b = 1396, and c = 1086 pm, Z = 8, Dx = 4.12 g cm−3. The structure is formed by the tendency of Cu(I) to form two collinear sp bonds to oxygen atoms which result in short O-Cu-O groups with the O-Cu bond length being approximately 196vpm. Due to the bonding properties of the Cu(I) metal the structure is built of layers of composition Cu2SO4. Due to the loss of only one electron and the bonding properties of copper(I) the structure is built up from four oxygen atoms of each sulfate group bonding to four other sulfate groups of the same layer via symmetrical O-Cu-O bridging.
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Atacamite is orthorhombic, space group Pnma, with two crystallographically independent Cu and hydroxyl oxygen atoms in the asymmetric unit. Both Cu atoms display characteristically Jahn-Teller distorted octahedral (4+2) coordination geometry: each Cu is bonded to four nearest OH groups with Cu-OH distance of 2.01Å; in addition, one of Cu atoms is bonded to two Cl atoms (at 2.76Å) to form a [Cu(OH)4Cl2] octahedron, and the other Cu atom is bonded to one Cl atom (at 2.75Å) and a distant OH group (at 2.36Å) to form a [Cu(OH)5Cl] octahedron. The two different types of octahedron are edge-linked to form a three- dimensional framework with the [Cu(OH)5Cl] octahedron cross-linking the [Cu(OH)4Cl2] octahedron layers parallel to (110) (Figure 1). Figure 1.
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According to the Blue Book, this chemical can be systematically named as 1,2,3,4,5,6-hexamethylbenzene. The locants (the numbers in front of the name) are superfluous, however, as the name hexamethylbenzene uniquely identifies a single substance and thus is the formal IUPAC name for the compound. It is an aromatic compound, with six π electrons (satisfying Hückel's rule) delocalised over a cyclic planar system; each of the six ring carbon atoms is sp2 hybridised and displays trigonal planar geometry, while each methyl carbon is tetrahedral with sp3 hybridisation, consistent with the empirical description of its structure. When recrystallised from ethanol, solid hexamethylbenzene occurs as colourless to white crystalline orthorhombic prisms or needles with a melting point of 165–166 °C, a boiling point of 268 °C, and a density of 1.0630 g cm−3.
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Using Boltzmann's principle, we conclude that :S_0 = Nk\ln(3/2), where k is the Boltzmann constant, which yields a value of 3.37 J mol−1 K−1, a value very close to the measured value. This estimate is 'naive', as it assumes the six out of 16 hydrogen configurations for oxygen atoms in the second set can be independently chosen, which is false. More complex methods can be employed to better approximate the exact number of possible configurations, and achieve results closer to measured values. By contrast, the structure of ice II is hydrogen-ordered, which helps to explain the entropy change of 3.22 J/mol when the crystal structure changes to that of ice I. Also, ice XI, an orthorhombic, hydrogen-ordered form of ice Ih, is considered the most stable form at low temperatures.
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Another derivative that reveals oxyselenide properties is β-La2O2MSe2 (M= Fe, Mn). This molecule possesses an orthorhombic structure (Figure 3), opening up the possibilities for different packing arrangements of oxyselenides. They are ferromagnetic at low temperatures (~27 K) and show high resistivity at room temperature. The Mn analogue, diluted in NaCl solution, suggests an optical band gap of 1.6 eV at room temperature, making it an insulator. Meanwhile, the band gap for the Fe analogue is approximately 0.7 eV between 150 K and 300 K, making it a semiconductor. In contrast, cobalt oxyselenide La2Co2O3Se2 is antiferromagnetically ordered, suggesting that although the different transition metals are responsible for the changes in an oxyselenide's magnetic property, the molecule's overall lattice structure may also influence its conductivity. Figure 4: Comparison of figure-of-merit ZT compounds Bi1-xMxCuSeO. Higher ZTs indicate more efficient energy conversions.
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The layered manganese oxide is constructed from corrugated layers of manganese/oxide octahedra and is electrochemically unstable. The distortions and deviation from truly planar metal oxide layers are a manifestation of the electronic configuration of the Mn(III) Jahn-Teller ion. I. Koetschau, M. N. Richard, J. R. Dahn, J. B. Soupart, J. C. Rousche "Orthorhombic LiMnO2 as a High Capacity Cathode for Li‐Ion Cells" J. Electrochemical Society volume 142(9) 2906-2910 (1995); doi: 10.1149/1.2048663 A layered variant, isostructural with LiCoO2, was prepared by Armstrong and Bruce in 1996 by ion exchange from the layered compound NaMnO2 A. Robert Armstrong, Peter G. Bruce "Synthesis of layered LiMnO2 as an electrode for rechargeable lithium batteries" Nature 381, p 499–500(1996)DOI: 10.1038/381499a0, however long term cycling and the defect nature of the charged compound led to structural degradation and cation equilibration to other phases.
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Crystal structure of OsB2 Osmium diboride (OsB2) has a high bulk modulus of 395 GPa and therefore is considered as a candidate superhard material, but the maximum achieved Vickers hardness is 37 GPa, slightly below the 40 GPa limit of superhardness. A common way to synthesize OsB2 is by a solid-state metathesis reaction containing a 2:3 mixture of OsCl3:MgB2. After the MgCl2 product is washed away, X-ray diffraction indicates products of OsB2, OsB and Os. Heating this product at 1,000 °C for three days produces pure OsB2 crystalline product. OsB2 has an orthorhombic structure (space group Pmmn) with two planes of osmium atoms separated by a non-planar layer of hexagonally coordinated boron atoms; the lattice parameters are a = 4.684 Å, b = 2.872 Å and c = 4.096 Å. The b direction of the crystal is the most compressible and the c direction is the least compressible.
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History of multiferroics: number of papers per year on magnetoelectrics or the magnetoelectric effect (in blue), and on multiferroics (in red) A Web of Science search for the term multiferroic yields the year 2000 paper "Why are there so few magnetic ferroelectrics?" from N. A. Spaldin (then Hill) as the earliest result. This work explained the origin of the contraindication between magnetism and ferroelectricity and proposed practical routes to circumvent it, and is widely credited with starting the modern explosion of interest in multiferroic materials . The availability of practical routes to creating multiferroic materials from 2000 stimulated intense activity. Particularly key early works were the discovery of large ferroelectric polarization in epitaxially grown thin films of magnetic BiFeO3, the observation that the non-collinear magnetic ordering in orthorhombic TbMnO3 and TbMn2O5 causes ferroelectricity, and the identification of unusual improper ferroelectricity that is compatible with the coexistence of magnetism in hexagonal manganite YMnO3.
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Mn2O3 is unlike many other transition metal oxides in that it does not adopt the corundum (Al2O3) structure. Two forms are generally recognized, α-Mn2O3 and γ-Mn2O3,Wells A.F. (1984) Structural Inorganic Chemistry 5th edition Oxford Science Publications although a high pressure form with the CaIrO3 structure has been reported too.High Pressure Phase transition in Mn2O3 to the CaIrO3-type Phase Santillan, J.; Shim, S. American Geophysical Union, Fall Meeting 2005, abstract #MR23B-0050 α-Mn2O3 has the cubic bixbyite structure, which is an example of a C-type rare earth sesquioxide (Pearson symbol cI80, space group Ia3, #206). The bixbyite structure has been found to be stabilised by the presence of small amounts of Fe3+, pure Mn2O3 has an orthorhombic structure (Pearson symbol oP24,space group Pbca, #61). α-Mn2O3 undergoes antiferromagnetic transition at 80 K. γ-Mn2O3 has a structure related to the spinel structure of Mn3O4 where the oxide ions are cubic close packed.
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Paulscherrerite is monoclinic (pseudo-orthrombic), with a = 4.288(2), b = 10.270(6), c = 6.885(5)Å, β = 90.39(4) = 90.39(4)o, V = 303.2(2)Å3, and Z = 4. No space group determination has been made, as no single-crystal study has been done. Given the very small crystallites (less than a few tens of nanometers), it is very difficult to distinguish an orthorhombic cell from a monoclinic cell with β close to 90° (Bevan et al. 2002). Possible space groups that explain all 46 reflections found include: P2, P21, P2/m, and P21/m. The structures of the closely related schoepite,Finch, R.J., Cooper, M.A., and Hawthorne, F.C. (1996) The crystal structure of schoepite, [(UO2)8O2(OH)12](H2O)12. Canadian Mineralogist, 34, 1071-1088. metaschoepiteWeller, M.T., Light, M.E., and Gelbrich, T. (2000) Structure of uranium(VI) Oxidedihydrate, UO32H2O; synthetic meta-schoepite (UO2)4O(OH)6 · 5H2O. Acta Crystallographica, B56, 577-583.
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The crystal structure of tantalum pentoxide has been the matter of some debate. The bulk material is disordered, being either amorphous or polycrystalline; with single crystals being difficult to grow. As such Xray crystallography has largely been limited to powder diffraction, which provides less structural information. At least 2 polymorphs are known to exist. A low temperature form, known as L- or β-Ta2O5, and the high temperature form known as H- or α-Ta2O5. The transition between these two forms is slow and reversible; taking place between 1000 and 1360 °C, with a mixture of structures existing at intermediate temperatures. The structures of both polymorphs consist of chains built from octahedral TaO6 and pentagonal bipyramidal TaO7 polyhedra sharing opposite vertices; which are further joined by edge-sharing. The overall crystal system is orthorhombic in both cases, with the space group of β-Ta2O5 being identified as Pna2 by single crystal X-ray diffraction. A high pressure form (Z-Ta2O5) has also been reported, in which the Ta atoms adopt a 7 coordinate geometry to give a monoclinic structure (space group C2).
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This reagent was originally prepared by Conrad Willgerodt by reacting iodobenzene with a mixture of acetic acid and peracetic acid: :CHI \+ CHCOH \+ CHCOH → CHI(OCCH) \+ HO PIDA can also be prepared from iodosobenzene and glacial acetic acid: :CHIO \+ 2 CHCOH → CHI(OCCH) \+ HO More recent preparations direct from iodine, acetic acid, and benzene have been reported, using either sodium perborate or potassium peroxydisulfate as the oxidizing agent: :CH \+ I \+ 2 CHCOH \+ KSO → CHI(OCCH) \+ KI \+ HSO \+ KHSO The PIDA molecule is termed hypervalent as its iodine atom (technically a hypervalent iodine) is in its +III oxidation state and has more than typical number of covalent bonds. It adopts a T-shaped molecular geometry, with the phenyl group occupying one of the three equatorial positions of a trigonal bipyramid (lone pairs occupy the other two) and the axial positions occupied by oxygen atoms from the acetate groups. The "T" is distorted in that the phenyl-C to I to acetate-O bond angles are less than 90°. A separate investigation of the crystal structure confirmed that it has orthorhombic crystals in space group Pnn2 and reported unit-cell dimensions in good agreement with the original paper.
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