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Salt Lake City, UT, United States

Kampf A.R.,Natural History Museum of Los Angeles County | Hughes J.M.,University of Vermont | Marty J.,5199 E. Silver Oak Rd. | Brown F.H.,University of Utah
Canadian Mineralogist | Year: 2013

Nashite, Na3Ca2[(V4+V5+ 9)O28].24H2O, is a new mineral species from the Little Eva mine, Yellow Cat District, Grand County, Utah, and the St. Jude mine, Slick Rock district, San Miguel County, Colorado, USA. Nashite occurs as blades on a corvusite-montroseite-bearing sandstone block intimately associated with calcite, gypsum, huemulite, pascoite, rossite, and sherwoodite. Nashite is bluish-green, with a light bluish-green streak. The mineral is transparent, with a subadamantine luster. Nashite does not fluoresce in short-or long-wave ultraviolet radiation, and has a hardness ca. 2. Nashite has a brittle tenacity, irregular fracture, and one good cleavage on {010}. Density (calc.) = 2.350 g/cm3 based on the empirical formula and single-crystal cell data, and density (calc.) = 2.343 g/cm3 based on the ideal formula and single-crystal cell data. Nashite is biaxial (-), with α 1.737(3), β 1.762(6), and γ 1.775(3). 2Vmeas = 70(2)° and 2V calc = 71°. Optic orientation is Y = b, X ≈ a. The mineral is pleochroic, with X greenish blue, Y yellowish green, and Z yellow, with X < Y < Z. Electron probe microanalysis and the crystal structure solution gave the empirical formula (based on O = 52): (Na3.063K 0.007)σ3.070(Ca1.984Sr 0.039)σ2.019[(V4+V5+ 9)O28].24(H1.995O). The simplified formula is Na3Ca2[(V4+V5+ 9)O 28].24H2O. Nashite is monoclinic, P21/n, with a 10.0099(3), b 21.8472(7), c 11.1504(7) A, and β 116.584(8)°. The strongest four lines in the diffraction pattern are [d in A(I)(hkl)]: 9.044(100)(111, 101), 8.350(64)(110), 10.995(46)(020), and 2.9942(29)(331, 332, 303, 071, 310). The atomic arrangement of nashite was solved and refined to R1 = 0.0293. The structural unit in nashite is a partially-reduced decavanadate group, with a composition of [(V4+V5+ 9)O28]7-; charge balance in the structure is maintained by the [Na3Ca2(OH2) 22.2H2O]7+ interstitial unit. The interstitial unit consists of chains of Na1 and Na2 octahedra and an irregular CaO 2(OH2)6 polyhedron. The chains are linked to the structural unit by direct bonding to oxygen atoms of the [(V 4+V5+ 9)O28]7- group and extensive hydrogen bonding between the H2O molecules of the interstitial group and the oxygen atoms of the structural unit. The mineral is named for Dr. Barbara P. Nash (b. 1944), Professor of Geology and Geophysics at the University of Utah. Source


Kampf A.R.,Natural History Museum of Los Angeles County | Hughes J.M.,University of Vermont | Nash B.,University of Utah | Marty J.,5199 E. Silver Oak Rd.
Canadian Mineralogist | Year: 2014

Kokinosite, Na2Ca2(V10O28)·24H2O, is a new mineral species from the St. Jude mine, Slick Rock district, San Miguel County, Colorado, USA. Kokinosite typically occurs as tablets or blades up to 0.05 mm thick, with stepped faces, and 1 mm in maximum dimension. Crystals are yellow orange, although sometimes they are tinted orange brown; the streak of the phase is yellow. The luster of kokinosite is subadamantine, and the mineral is transparent; it does not fluoresce in short- or long-wave radiation. The Mohs hardness is ca. 1 1/2. Kokinosite possesses a brittle tenacity, and displays one good cleavage on {011¯}. No parting was observed, and fracture is irregular. Density (calc.) = 2.353 g cm-3 on the basis of the empirical formula and the single-crystal cell data. Kokinosite is biaxial (-), with α 1.725(3), β 1.770(5), and γ 1.785(3). The 2V was measured as 56.6(3)° from extinction data, and 2Vcalc = 58.7° . Dispersion is r < v, moderate. The optic orientation was incompletely determined, with X ^ a = 15° , Y ≈ b. The mineral is pleochroic: X, Z = orange yellow, Y = orange, and X = Z < Y. Electron probe microanalysis and the crystal structure solution gave the empirical formula (based on V = 10 and O = 52 apfu) (Na1.88K0.01)Ʃ1.89(Ca1.81Sr0.12)Ʃ1.93(V10O28)·24H2O. The simplified structural formula is Na2Ca2(V10O28)·24H2O. Kokinosite is triclinic, P1¯, with a 8.74899(19), b 10.9746(3), c 12.8216(9)Å, α 114.492(8), β 105.093(7), γ 91.111(6)° , V 1070.25(11) Å3, and Z = 1. The strongest four lines in the diffraction pattern are [d in Å(I)(hkl)]: 9.88(100)(010, 01¯1), 7.92(36)(1¯01), 8.42(33)(100), and 6.01(31)(11¯1, 110). The atomic arrangement of kokinosite was solved and refined to R1 = 0.0379 for 3806 Fo > 4σF reflections. The structural unit is a decavanadate polyanion, (V10O28)6-; charge balance in the structure is maintained by the [Na2Ca2(H2O)24]6+ interstitial unit that exists as Na(H2O)6 octahedra and Ca(H2O)8 polyhedra that link into chains by edge- and corner-sharing. The linkage between the structural unit and the interstitial unit occurs solely by hydrogen bonding. The new mineral is named in honor of Michael Kokinos (b. 1927) of Shingle Springs, California, a well-known mineral collector and member of the Micromounters' Hall of Fame. Source


Kampf A.R.,Natural History Museum of Los Angeles County | Hughes J.M.,University of Vermont | Marty J.,5199 E. Silver Oak Rd. | Nash B.,University of Utah
Canadian Mineralogist | Year: 2012

Postite, Mg(H2O)6Al2(OH) 2(H2O)8(V10O28) •13H2O, is a new mineral species from the Vanadium Queen mine, La Sal Creek Canyon, and the Blue Cap mine, Lyon Canyon Creek, San Juan County, Utah, U.S.A. Postite occurs as very thin, needle-like prisms with pyramidal terminations; crystals commonly occur in parallel bundles and grow in divergent and "jackstraw" masses. Individual crystals are up to 1 mm long and 50 μm in diameter, and are golden-yellow with a yellow streak. The mineral is transparent, with a subadamantine luster; it does not fluoresce in short- or long-wave ultraviolet radiation. Postite has a Mohs hardness of approximately 2 and brittle tenacity. The mineral has one good cleavage on {001} and at least two perfect cleavages parallel to [001], possibly {100} and {010}. The fracture is splintery. The density calculated from the empirical formula using the single-crystal cell data is 2.226 g/cm3. Postite is biaxial (+) with a 2V angle of 71°. Indices of refraction for postite are α 1.727(3), β 1.733(3), and γ 1.745(3). The optical orientation is X = c, Y = b, Z = a. Dispersion was not observed and pleochroism was not perceptible. Electron probe microanalysis and the crystal structure solution gave the empirical formula (Mg0.97Na0.06Ca0.04Sr 0.01K0.01)Σ1.09Al1.94 [(OH) 1.92(H2O)0.08]Σ2.00 (V 10O28)•27H2O. The simplified structural formula of postite is Mg(H2O)6Al2(OH)2(H 2O)8(V10O28) •13H2O. Postite is orthorhombic, Pccn, with a 16.3357(6), b 24.2434(17), c 11.7343(4) Å, V 4647.2(4) Å3, and Z = 4. The strongest four lines in the diffraction pattern are [d in Å(I)(hkl)]: 8.937(100)(111), 12.190(90)(020), 3.771(24)(113), and 8.248(22)(200). The atomic arrangement of postite was solved and refined to R1 = 0.0358. The structural unit is a decavanadate polyanion, [V10O28]6-; charge balance in the structure is maintained by the [Mg(H2O) 6Al2(OH)2(H2O)8 •13 H2O]6+ interstitial unit. The interstitial unit consists of a [Mg(H2O)6]2+ monomer, an [Al 2(OH)2(H2O)8]4+ edge-sharing dimer, and thirteen additional H2O molecules. The linkage between the structural unit and the interstitial unit results from hydrogen bonding between oxygen atoms of the structural unit with hydrogen atoms of the [Al 2(OH)2(H2O)8]4+ edge-sharing dimer and those of isolated H2O molecules. The new mineral is named in honor of Dr. Jeffrey E. Post (b. 1954), Curator-in-Charge of the National Gem and Mineral Collection, U. S. National Museum of Natural History (Smithsonian Institution). DOI: 10.3749/canmin.50.1.45. Source


Kampf A.R.,Natural History Museum of Los Angeles County | Hughes J.M.,University of Vermont | Marty J.,5199 E. Silver Oak Rd. | Nash B.,University of Utah
Canadian Mineralogist | Year: 2013

Wernerbaurite, {[Ca(H2O)7]2(H 2O)2(H3O)2}{V10O 28}, and schindlerite, {[Na2(H2O) 10](H3O)4}{V10O28}, are new mineral species from the St. Jude mine, Slick Rock district, San Miguel County, Colorado, U.S.A. Crystals of wernerbaurite are tabular on {100} with stepped faces and square to octagonal outlines, up to about 1 mm in maximum dimension; the crystals are yelloworange and the streak is yellow. The mineral displays a subadamantine luster, and is transparent; it does not fluoresce in short- or long-wave ultraviolet radiation. Wernerbaurite has a hardness of about 2, a brittle tenacity, and irregular fracture; two good cleavages, {100} and {010}, were observed. The density calculated from the empirical formula using the single-crystal cell data is 2.352 g cm-3. Wernerbaurite is biaxial (-), with α 1.745(3), β 1.780(3), and γ 1.795(3); 2V 66(2)° (white light). Dispersion is r > v, very strong. Optical orientation: X ∧ a = 29°, Y ∧ c = 44°, Z ∧ b = 46°; pleochroism: X, Z = yellow, Y = orange; X = Z < Y. Electron probe microanalysis and the crystal structure solution provided the empirical formula {(Ca1.88Na 0.14K0.03Sr0.02) σ2.07(H 2O)15.95(H3O)2.05}{V 10O28} (based on V5+ = 10 and O = 46). The simplified structural formula of wernerbaurite is {[Ca(H2O) 7]2(H2O)2(H3O) 2}{V10O28}. Wernerbaurite is triclinic, P1, with a 9.7212(6), b 10.2598(8), c 10.5928(8) Å, α 89.999(6)°, β 77.083(7)°, y 69.887(8)°, V 963.55(12) Å3, and Z = 1. The strongest four lines in the diffraction pattern [d in Å(I)(hkl)] are: 10.32(100)(001), 8.88(95)(100), 9.64(92)(010), and 6.881(70)(111). The atomic arrangement of wernerbaurite was refined to R1 = 0.0341 on the basis of 3,440 diffractions with F0 > 4σF. The structural unit is a decavanadate polyanion. (V10O28)6-. The interstitial unit linking the structural units has a composition of {[Ca(H2O)7]2(H2O)2(H 3O)2}6+, and is formed of an isolated [Ca(H22O)7]2+ polyhedron, a (H 3O)+ ion, and an isolated H2O molecule. Wernerbaurite is named in honor of Prof. Dr. rer. nat. Werner H. Baur for his long, productive and distinguished career in mineralogical crystallography. Crystals of schindlerite are tabular and commonly occur in stacked parallel intergrowths up to 0.3 mm in maximum dimension; the crystals are orange with a yellow streak. Schindlerite displays a subadamantine luster, and is transparent; it does not fluoresce in short- or long-wave ultraviolet radiation. Schindlerite has a hardness of about 2, a brittle tenacity, and one good cleavage on {010}. The density calculated from the empirical formula using the single-crystal cell data is 2.461 g cm-3. Schindlerite is biaxial (+), with α 1.74 (est), β 1.790(5), and γ 1.875 (calc); 2V (meas) = 78.1° (white light). Dispersion is r > v, very strong. The optical orientation is X ∧ b = 25°, Y ∧ c = 12°, Z ∧ a = 3°. No pleochroism was perceptible. Electron probe microanalysis and the crystal structure solution provided the empirical formula {[(Na 1.58K0.35Ca0.02Sr0.01)z 1.96(H2O)10.00] (H3O) 4}{V10O28} (based on V-5 = 10 and O = 42). The simplified structural formula of schindlerite is {[Na 2(H2O)10](H3O)4}{V 10O28}. Schindlerite is triclinic, Pi, with a 8.5143(3), b 10.4283(5), c 11.2827(8) Å, α 68.595(5)°, β 87.253(6)°, y 67.112(5)°, V 854.08(8) Å3, and Z = 1. The strongest four lines in the diffraction pattern [d in Å(I)(hkl)] are: 8.68(100)(010, 011), 10.51(94)(001), 7.70(86)(100,110), and 6.73(61)(111,101). The atomic arrangement of schindlerite was refined to R1 = 0.0399. The structural unit is a decavanadate polyanion, (V10O 28)10. The interstitial unit linking the structural units has a composition of {[Na2(H2O)10](H 3O)4}6+, and is formed of a [Na 2(H2O)10] dimer decorated with four hydronium ions. As in wernerbaurite, an extensive network of hydrogen bonding links the interstitial unit to the structural unit in schindlerite. Schindlerite is named in honor of Dr. Michael Schindler, Associate Professor for Environmental Mineralogy at Laurentian University, Sudbury, Ontario, who has contributed greatly to our understanding of vanadium mineralogy. Wernerbaurite and schindlerite are the first hydronium-bearing decavanadate minerals, and both minerals are natural analogs of previously described synthetic phases. Source


Kampf A.R.,Natural History Museum of Los Angeles County | Hughes J.M.,University of Vermont | Marty J.,5199 E. Silver Oak Rd. | Nash B.P.,University of Utah | And 2 more authors.
Canadian Mineralogist | Year: 2014

Bluestreakite, K4Mg2(V25+V85+O28)·14H2O, is a new mineral species from the Blue Streak mine, Bull Canyon, Montrose County, Colorado, USA. Bluestreakite typically occurs as irregular polycrystalline coatings on rounded quartz grains or masses of montroseite, and rarely as tablets or blades. It grows on corvusite-montroseite-bearing sandstone blocks intimately associated with gypsum, huemulite, hummerite, metamunirite, and munirite. Bluestreakite is dark greenish blue, with a light blue streak. The mineral is transparent, with a subadamantine luster. Bluestreakite does not fluoresce in short- or long-wave ultraviolet radiation, and it has a hardness ca. 2. Bluestreakite has a brittle tenacity, irregular fracture, and no cleavage. Density (calc.) = 2.630 g·cm-3 based on the empirical formula and single-crystal cell data. Bluestreakite is biaxial (-), with α 1.750(5), β 1.800(5), γ 1.829 (calc.) (white light); 2Vmeas. = 73(3)°. Optic orientation is Z = b (X and Y not determined). The pleochroism is slight, with X < Y ≈ Z dark greenish blue. Electron probe microanalysis gave the empirical formula (based on O = 42) (K3.37Na0.15)Σ3.52Mg1.94(V1.404+V8.605+)O28·14H2O. Bluestreakite is monoclinic, P21/n, with a 12.2383(7), b 10.3834(4), c 14.1945(6) Å, β 103.008(2)°, V 1757.48(14) Å3, and Z = 2. The strongest four lines in the diffraction pattern are [d in Å(I)(hkl)]: 10.34(57)(1¯01), 8.27(100)(011,101), 7.90(21)(110), and 1.9814(22)(1¯17,2¯17). The atomic arrangement of bluestreakite was solved and refined to R1 = 0.0339 for 7395 independent reflections with F > 4σ (F). The structural unit in bluestreakite is a partially reduced decavanadate group, with an ideal composition of [(V24+V85+)O28]8-; charge balance in the structure is maintained by the [K4Mg2·14H2O]8+ interstitial complex. The interstitial complex is formed of irregular K1[O4(H2O)4] and K2[O6(H2O)3] polyhedra, and a Mg(H2O)6 octahedron. Bonding between the interstitial complex and the structural unit takes place through direct bonding of the K1 and K2 atoms of the interstitial complex with the oxygen atoms of the structural unit, as well as extensive hydrogen bonding. Source

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