Shumwayite, [(UO2)(SO4)(H2O)2]2·H2O, a new uranyl sulfate mineral from Red Canyon, San Juan County, Utah, USA

2017 ◽  
Vol 81 (2) ◽  
pp. 273-285 ◽  
Author(s):  
Anthony R. Kampf ◽  
Jakub Plášil ◽  
Anatoly V. Kasatkin ◽  
Joe Marty ◽  
Jiří Čejka ◽  
...  
Keyword(s):  
Crystal Structure ◽  
Energy Dispersive Spectrometer ◽  
New Mineral ◽  
San Juan ◽  
Uranium Deposits ◽  
Uranyl Sulfate ◽  
Calculated Density ◽  
Secondary Alteration ◽  
Mohs Hardness ◽  
San Juan County

AbstractThe new mineral shumwayite (IMA2015-058), [(UO2)(SO4)(H2O)2]2·H2O, was found in the Green Lizard and Giveaway-Simplot mines, White Canyon district, San Juan County, Utah, USA, where it occurs as a secondary alteration phase. At the Green Lizard mine, it is found in association with calcite, gypsum, plášilite, pyrite, rozenite and sulfur; at the Giveaway-Simplot mine, shumwayite is associated with rhomboclase and römerite. The mineral occurs as pale greenish-yellow monoclinic prisms, elongated on [100], up to ∼0.3 mm long and commonly in subparallel to random intergrowths. The mineral is transparent with a vitreous lustre and has a white streak. It fluoresces bright greenish white under both longwave and shortwave ultraviolet radiation. The Mohs hardness is ∼2. Crystals are brittle with perfect {011} cleavage and irregular fracture. The mineral is slightly deliquescent and is easily soluble in room temperature H2O. The calculated density is 3.844 g cm–3. Optically, shumwayite is biaxial (+/–), with α = 1.581(1), β= 1.588(1), γ = 1.595(1) (measured in white light). The measured 2Vxbased on extinction data collected on a spindle stage is 89.8(8)°; the calculated 2Vxis 89.6°. Dispersion is strong, but the sense is not defined because the optic sign is ambiguous. No pleochroism was observed. The optical orientation isX=b,Y=c,Z=a. Energy-dispersive spectrometer analyses (with H2O based on the crystal structure) yielded the empirical formula U2.01S1.99O12.00·5H2O.Shumwayite is monoclinic,P21/c,a= 6.74747(15),b= 12.5026(3),c= 16.9032(12) Å, β = 90.919(6)°,V= 1425.79(11) Å3andZ= 4. The crystal structure (R1= 1.88% for 2936F> 4σF) contains UO7pentagonal bipyramids and SO4tetrahedra that link by corner-sharing to form [(UO2)(SO4)(H2O)2] chains along [100]. The chains and isolated H2O groups between them are linked together only by hydrogen bonds. The mineral is named in honour of the Shumway family, whose members account for the discovery and mining of hundreds of uranium deposits on the Colorado Plateau, including the Green Lizard mine.

Greenlizardite, (NH4)Na(UO2)2(SO4)2(OH)2·4H2O, a new mineral with phosphuranylite-type uranyl sulfate sheets from Red Canyon, San Juan County, Utah, USA

2018 ◽  
Vol 82 (2) ◽  
pp. 401-411 ◽  
Author(s):  
Anthony R. Kampf ◽  
Jakub Plášil ◽  
Barbara P. Nash ◽  
Joe Marty
Keyword(s):  
Crystal Structure ◽  
New Mineral ◽  
San Juan ◽  
Uranyl Sulfate ◽  
Calculated Density ◽  
Secondary Alteration ◽  
Pale Yellow ◽  
Light Yellow ◽  
Mohs Hardness ◽  
San Juan County

ABSTRACTThe new mineral greenlizardite (IMA2017-001), (NH4)Na(UO2)2(SO4)2(OH)2·4H2O, was found in the Green Lizard mine, Red Canyon, San Juan County, Utah, USA, where it occurs as a secondary alteration phase. It is associated with ammoniozippeite, boussingaultite and dickite. It forms as light green-yellow blades up to ~0.3 mm long. The mineral is vitreous and transparent with a white streak. It fluoresces greenish blue in 405 nm light. Mohs hardness is ~2. Crystals are brittle with irregular fracture and two cleavages: perfect {001} and good {2$\bar 1$0}. Greenlizardite is easily soluble in room-temperature H2O. The calculated density is 3.469 g cm–3. Optically, it is biaxial (+) with α = 1.559(1), β = 1.582(1) and γ = 1.608(1) (measured in white light). The measured 2V is 88(1)°; the calculated 2V is 87.8°. Dispersion is moderate, r < v. Pleochroism is X = very pale yellow green, Y = pale yellow green and Z = light yellow green; X < Y < Z. The optical orientation is X ≈ c, Y ≈ a and Z ≈ b*. The Raman spectrum exhibits bands attributable to both sulfate and uranyl groups. Electron probe microanalyses (with H2O based on the crystal structure) yielded (NH4)0.98Na1.00U1.96S2.04O18.00H10.02. Greenlizardite is triclinic, P$\bar 1$, a = 6.83617(17), b = 9.5127(3), c = 13.8979(10) Å, α = 98.636(7), β = 93.713(7), γ = 110.102(8)°, V = 832.49(8) Å3 and Z = 2. The crystal structure (R1 = 2.39% for 2542 I > 2σI) contains edge-sharing dimers of UO7 pentagonal bipyramids. The dimers link by sharing corners with SO4 groups to form a [(UO2)2(SO4)2(OH)2]2– sheet based on the phosphuranylite anion topology. Zig-zag edge-sharing chains of NaO6 octahedra link adjacent [(UO2)2(SO4)2(OH)2]2– sheets, forming thick slabs. NH4 bonds to O atoms in adjacent slabs linking them together. H2O groups occupy channels in the slabs and space between the slabs.

Belakovskiite, Na7(UO2)(SO4)4(SO3OH)(H2O)3, a new uranyl sulfate mineral from the Blue Lizard mine, San Juan County, Utah, USA

2014 ◽  
Vol 78 (3) ◽  
pp. 639-649 ◽  
Author(s):  
A. R. Kampf ◽  
J. Plášil ◽  
A. V. Kasatkin ◽  
J. Marty
Keyword(s):  
Microprobe Analysis ◽  
Electron Microprobe Analysis ◽  
New Mineral ◽  
San Juan ◽  
Uranyl Sulfate ◽  
Calculated Density ◽  
Secondary Alteration ◽  
X Ray ◽  
Mohs Hardness ◽  
San Juan County

AbstractThe new mineral belakovskiite (IMA2013-075), Na7(UO2)(SO4)4(SO3OH)(H2O)3, was found in the Blue Lizard mine, Red Canyon, White Canyon district, San Juan County, Utah, USA, where it occurs as a secondary alteration phase in association with blödite, ferrinatrite, kröhnkite, meisserite and metavoltine. Crystals of belakovskiite are very pale yellowish-green hair-like fibres up to 2 mm long and usually no more than a few mm in diameter. The fibres are elongated on [100] and slightly flattened on {021}. Crystals are transparent with a vitreous lustre. The mineral has a white streak and a probable Mohs hardness of ∼2. Fibres are flexible and elastic, with brittle failure and irregular fracture. No cleavage was observed. The mineral is readily soluble in cold H2O. The calculated density is 2.953 g cm−3. Optically, belakovskiite is biaxial (+) with α = 1.500(1), β = 1.511(1) and γ = 1.523(1) (measured in white light). The measured 2V is 87.1(6)° and the calculated 2V is 88°. The mineral is non-pleochroic. The partially determined optical orientation is X ≈ a. Electron-microprobe analysis provided Na2O 21.67, UO3 30.48, SO3 40.86, H2O 6.45 (structure), total 99.46 wt.% yielding the empirical formula Na6.83(U1.04O2)(SO4)4(S0.99O3OH)(H2O)3 based on 25 O a.p.f.u. Belakovskiite is triclinic, P, with a = 5.4581(3), b = 11.3288(6), c = 18.4163(13) Å, α = 104.786(7)°, β = 90.092(6)°, γ = 96.767(7)°, V = 1092.76(11) Å3 and Z = 2. The eight strongest X-ray powder diffraction lines are [dobs Å(I)(hkl)]: 8.96(35)(002), 8.46(29)(011), 5.19(100)(01,101,10), 4.66(58)(013,02,0,110), 3.568(37)(120,023,005,03), 3.057(59)(06,15,31), 2.930(27)(multiple) and 1.8320(29)(multiple). The structure, refined to R1 = 5.39% for 3163 Fo > 4σF reflections, contains [(UO2)(SO4)4(H2O)]6− polyhedral clusters connected via an extensive network of Na−O bonds and H bonds involving eight Na sites, three other H2O sites and an SO3OH (hydrosulfate) group. The 3-D framework, thus defined, is unique among known uranyl sulfate structures. The mineral is named for Dmitry Ilych Belakovskiy, a prominent Russian mineralogist and Curator of the Fersman Mineralogical Museum.

Alwilkinsite-(Y), a new rare-earth uranyl sulfate mineral from the Blue Lizard mine, San Juan County, Utah, USA

2017 ◽  
Vol 81 (4) ◽  
pp. 895-907 ◽  
Author(s):  
Anthony R. Kampf ◽  
Jakub Plášil ◽  
Jiří Čejka ◽  
Joe Marty ◽  
Radek Škoda ◽  
...  
Keyword(s):  
New Mineral ◽  
San Juan ◽  
X Ray Diffraction ◽  
Uranyl Sulfate ◽  
Calculated Density ◽  
Secondary Alteration ◽  
X Ray ◽  
Perfect Cleavage ◽  
Mohs Hardness ◽  
San Juan County

AbstractThe new mineral alwilkinsite-(Y) (IMA2015-097), Y(H2O)7[(UO2)3(SO4)2O(OH)3]·7H2O, was found in the Blue Lizard mine, San Juan County, Utah, USA, where it occurs as a secondary alteration phase.The mineral is slightly flexible before brittle failure with splintery fracture and perfect cleavage parallel to [010], has Mohs hardness of ∼2–2½, exhibits dull greenish-grey fluorescence and has a calculated density of 3.371 g cm–3. Alwilkinsite-(Y) occursas yellowish-green needles, elongate on [010], with domatic terminations and exhibits the forms {102}, {301} and {124}. It is optically biaxial (+) with α = 1.573(1), β = 1.581(1), γ = 1.601(1) (white light), the measured 2V is 65.3(1)°, the dispersion is r<v (weak), the optical orientation is X = c, Y = a, Z = b and there is no pleochroism. Electron microprobe analyses yielded the empirical formula (Y0.66Dy0.08Gd0.06Er0.05Nd0.03Yb0.03Sm0.02Ce0.01)∑0.94(H2O)7[(UO2)3(S1.01O4)2O(OH)3]·7H2O.The eight strongest powder X-ray diffraction lines are [dobs Å(I)(hkl)]: 9.88(100)(101,002), 7.47(13)(102), 5.621(17)(103,201), 4.483(18)(104), 3.886(14)(130,222), 3.322(46)(multiple), 3.223(13)(multiple) and 3.145(16)(034). Alwilkinsite-(Y) is orthorhombic,P212121, a = 11.6194(5), b = 12.4250(6), c = 19.4495(14) Å, V = 2807.9(3) Å3 and Z = 4. The structure of alwilkinsite-(Y) (R1 = 0.042 for 4244 Fo > 4σF)contains edge-sharing chains of uranyl bipyramids with outlying sulfate tetrahedra that are similar to the chain linkages within the uranyl sulfate sheets of the zippeite structure. Short segments of the uranyl sulfate chains in the alwilkinsite-(Y) structure have the same topology as portionsof the uranyl sulfate linkages in uranopilite. Alwilkinsite-(Y) is named for Alan (Al) J. Wilkins, MD (born 1955), the discoverer of the mineral.

Feynmanite, a new sodium uranyl sulfate mineral from Red Canyon, San Juan County, Utah, USA

2018 ◽  
Vol 83 (02) ◽  
pp. 153-160 ◽  
Author(s):  
Anthony R. Kampf ◽  
Travis A. Olds ◽  
Jakub Plášil ◽  
Joe Marty ◽  
Samuel N. Perry
Keyword(s):  
Secondary Phase ◽  
New Mineral ◽  
San Juan ◽  
Uranyl Sulfate ◽  
Calculated Density ◽  
Laser Crystals ◽  
Perfect Cleavage ◽  
Mohs Hardness ◽  
San Juan County ◽  
Pale Green

AbstractThe new mineral feynmanite, Na(UO2)(SO4)(OH)·3.5H2O, was found in both the Blue Lizard and Markey mines, San Juan County, Utah, USA, where it occurs as a secondary phase on pyrite-rich asphaltum in association with chinleite-(Y), gypsum, goethite, natrojarosite, natrozippeite, plášilite, shumwayite (Blue Lizard) and wetherillite (Markey). The mineral is pale greenish yellow with a white streak and fluoresces bright greenish white under a 405 nm laser. Crystals are transparent with a vitreous lustre. It is brittle, with a Mohs hardness of ~2, irregular fracture and one perfect cleavage on {010}. The calculated density is 3.324 g cm–3. Crystals are thin needles or blades, flattened on {010} and elongate on [100], exhibiting the forms {010}, {001}, {101} and {10$\bar{1}$}, and are up to ~0.1 mm in length. Feynmanite is optically biaxial (–), with α = 1.534(2), β = 1.561(2) and γ = 1.571(2) (white light); 2Vmeas.= 62(2)°; no dispersion; and optical orientation:X=b,Y≈a,Z≈c. It is weakly pleochroic:X= colourless,Y= very pale green yellow andZ= pale green yellow (X&lt;Y&lt;Z). Electron microprobe analyses (WDS mode) provided (Na0.84Fe0.01)(U1.01O2)(S1.01O4)(OH)·3.5H2O. The five strongest powder X-ray diffraction lines are [dobsÅ(I)(hkl)]: 8.37(100)(010), 6.37(33)($\bar{1}$01,101), 5.07(27)($\bar{1}$11,111), 4.053(46)(004,021) and 3.578(34)(120). Feynmanite is monoclinic, has space groupP2/n,a= 6.927(3),b= 8.355(4),c= 16.210(7) Å, β = 90.543(4)°,V= 938.1(7) Å3andZ= 4. The structure of feynmanite (R1= 0.0371 for 1879Io&gt; 2σI) contains edge-sharing pairs of pentagonal bipyramids that are linked by sharing corners with SO4groups, yielding a [(UO2)2(SO4)2(OH)2]2–sheet based on the phosphuranylite anion topology. The sheet is topologically identical to those in deliensite, johannite and plášilite. The dehydration of feynmanite to plášilite results in interlayer collapse involving geometric reconfiguration of the sheets and the ordering of Na.

Meisserite, Na5(UO2)(SO4)3(SO3OH)(H2O), a new uranyl sulfate mineral from the Blue Lizard mine, San Juan County, Utah, USA

2013 ◽  
Vol 77 (7) ◽  
pp. 2975-2988 ◽  
Author(s):  
J. Plášil ◽  
A. R. Kampf ◽  
A. V. Kasatkin ◽  
J. Marty ◽  
R. Škoda ◽  
...  
Keyword(s):  
Empirical Formula ◽  
Inorganic Compounds ◽  
New Mineral ◽  
San Juan ◽  
Uranyl Sulfate ◽  
Calculated Density ◽  
Pale Yellow ◽  
Mohs Hardness ◽  
Stretching Vibrations ◽  
San Juan County

AbstractMeisserite (IMA2013-039), Na5(UO2)(SO4)3(SO3OH)(H2O), is a new uranyl sulfate mineral from the Blue Lizard mine, San Juan County, Utah (USA). It is named in honour of the prominent Swiss mineralogist Nicolas Meisser. The new mineral was found in a sandstone matrix and is associated with chalcanthite, copiapite, ferrinatrite, gypsum, johannite and another new Na-bearing uranyl sulfate, belakovskiite (IMA2013-075). Meisserite is a secondary mineral formed by the post-mining weathering of uraninite. The mineral is triclinic, P, a = 5.32317(10), b = 11.5105(2), c = 13.5562(10) Å, α = 102.864(7)°, β = 97.414(7)°, γ = 91.461(6)°, V = 801.74(6) Å3, and Z = 2. Crystals are prisms elongated on [100], up to 0.3 mm long, exhibiting the forms {010} and {001}. Meisserite is pale green to yellowish green, translucent to transparent and has a very pale yellow streak. It is brittle, with fair cleavage on {100} and {001}, and uneven fracture. The Mohs hardness is estimated at 2. Meisserite is somewhat hygroscopic and easily soluble in water. The calculated density based on the empirical formula is 3.208 g/cm3. Meisserite exhibits bright yellow green fluorescence under both long- and shortwave UV radiation. The mineral is optically biaxial (–), with α = 1.514(1), β = 1.546(1), γ = 1.557(1) (measured in white light). The measured 2V is 60(2)° and the calculated 2V is 60°. Dispersion is r > v, perceptible, and the optical orientation is X ≈ a, Z ≈ c*. The mineral is pleochroic, with X (colourless) < Y (pale yellow) ≈ Z (pale greenish yellow). The empirical formula of meisserite (based on 19 O a.p.f.u.) is Na5.05(U0.94O2)(SO4)3[SO2.69(OH)1.31](H2O). The Raman spectrum is dominated by the symmetric stretching vibrations of UO22+, SO42– and also weaker O–H stretching vibrations. The eight strongest powder X-ray diffraction lines are [dobs in Å (hkl)Irel]: 13.15 (001) 81, 6.33 (02) 62, 5.64 (01,020) 52, 5.24 (100,012,01) 100, 4.67 (101) 68, 3.849 (1,102,022) 48, 3.614 (03¯2,3) 41, and 3.293 (13,004) 43. The crystal structure of meisserite (R1 = 0.018 for 3306 reflections with Iobs > 3σI) is topologically unique among known structures of uranyl minerals and inorganic compounds. It contains uranyl pentagonal bipyramids linked by SO4 groups to form chains. Na+ cations bond to O atoms in the chains and to an SO3OH group and an H2>O group between the chains, thereby forming a heteropolyhedral framework.

Pseudomeisserite-(NH4), a new mineral with a novel uranyl-sulfate linkage from the Blue Lizard mine, San Juan County, Utah, USA

2020 ◽  
Vol 84 (3) ◽  
pp. 435-443
Author(s):  
Anthony R. Kampf ◽  
Travis A. Olds ◽  
Jakub Plášil ◽  
Barbara P. Nash ◽  
Joe Marty
Keyword(s):  
New Mineral ◽  
San Juan ◽  
Optical Orientation ◽  
Uranyl Sulfate ◽  
X Ray ◽  
Pale Yellow ◽  
Light Yellow ◽  
Perfect Cleavage ◽  
Mohs Hardness ◽  
San Juan County

AbstractThe new mineral pseudomeisserite-(NH4) (IMA2018-166), (NH4,K)2Na4[(UO2)2(SO4)5]⋅4H2O, was found in the Blue Lizard mine, San Juan County, Utah, USA, where it occurs as light yellow prisms in a secondary assemblage with belakovskiite, blödite, changoite, ferrinatrite, gypsum, ivsite, metavoltine and tamarugite. The streak is very pale yellow and the fluorescence is bright lime green under 405 nm ultraviolet light. Crystals are transparent with vitreous lustre. The tenacity is brittle, the Mohs hardness is 2½, the fracture is curved or conchoidal and there is one perfect cleavage on {100}. The mineral is easily soluble in H2O and has a measured density of 3.22(2) g⋅cm–3. Pseudomeisserite-(NH4) is optically biaxial (–) with α = 1.536(2), β = 1.559(2) and γ = 1.565(2) (white light); 2Vmeas. = 53(1)°; dispersion is r > v, distinct; pleochroism: X colourless, Y light yellow and Z pale yellow (X < Z < Y); optical orientation: Z = b, Y ∧ c = 33° in obtuse β). Electron microprobe analyses (WDS mode) provided (NH4)1.49K0.60Na3.87U2.00S5.04O28H7.78. The five strongest X-ray powder diffraction lines are [dobs, Å(I)(hkl)]: 12.69(76)(100), 6.83(84)(012,102), 6.01(100)($\bar{2}$02), 3.959(67)($\bar{2}$21,$\bar{2}$14,$\bar{1}$23) and 3.135(76)($\bar{2}$06,223,$\bar{1}$16). Pseudomeisserite-(NH4) is monoclinic, P21/c, a = 13.1010(3), b = 10.0948(2), c = 19.4945(14) Å, β = 104.285(7)°, V = 2498.5(2) Å3 and Z = 4. The structural unit in the structure (R1 = 0.0254 for 3837 I > 2σI reflections) is a novel [(UO2)2(SO4)5]6– uranyl-sulfate band.

Lussierite, a new sodium uranyl sulfate mineral with bidentate UO7–SO4linkage from the Blue Lizard mine, San Juan County, Utah, USA

2019 ◽  
Vol 83 (6) ◽  
pp. 799-808 ◽  
Author(s):  
Anthony R. Kampf ◽  
Travis A. Olds ◽  
Jakub Plášil ◽  
Barbara P. Nash ◽  
Joe Marty
Keyword(s):  
Pentagonal Bipyramid ◽  
New Mineral ◽  
San Juan ◽  
Charge Balance ◽  
Uranyl Sulfate ◽  
Wavelength Dispersive Spectroscopy ◽  
X Ray ◽  
Mohs Hardness ◽  
San Juan County ◽  
Pale Green

AbstractThe new mineral lussierite (IMA2018-101), Na10[(UO2)(SO4)4](SO4)2(H2O)3, was found in the Blue Lizard mine, San Juan County, Utah, USA, where it occurs as pale green–yellow prisms or blades in a secondary assemblage with belakovskiite, ferrinatrite, halite, ivsite, metavoltine and thénardite. The streak is white and the fluorescence is bright cyan under 365 nm ultraviolet light. Crystals are transparent with vitreous lustre. The tenacity is brittle, the Mohs hardness is 2½, the fracture is irregular and no cleavage was observed. The mineral is easily soluble in H2O and has a measured density of 2.87(2) g cm–3. Lussierite is optically biaxial (+), with α = 1.493(1), β = 1.505(1) and γ = 1.518(1) (white light); 2Vmeas.= 88(1)°; dispersion isr>v, moderate; pleochroism:X= colourless,YandZ= green yellow (X<Y≈Z); optical orientation:X=b,Z∧a= 44° in obtuse β. Electron microprobe analyses (wavelength-dispersive spectroscopy mode) provided Na10(U0.99O2)(S1.00O4)6·3H2O (+0.06 H for charge balance). The five strongest X-ray powder diffraction lines are [dobsÅ(I)(hkl)]: 6.69(95)($\bar{1}$11,130), 4.814(100)(150,002,060), 3.461(83)(171,$\bar{2}$02), 2.955(81)(113,330) and 2.882(74)($\bar{1}$91,311,191,0·10·0). Lussierite is monoclinic,Cc,a= 9.3134(4),b= 28.7501(11),c= 9.6346(7) Å, β = 93.442(7)°,V= 2575.1(2) Å3andZ= 4. The structure (R1= 0.0298 for 5202I> 2σI) contains a [(UO2)(SO4)4]6–uranyl sulfate cluster in which one SO4tetrahedron shares an edge (bidentate linkage) with the UO7pentagonal bipyramid. The uranyl sulfate clusters occur in layers and are linked through a complex network of bonds involving Na+cations, isolated SO4tetrahedra and isolated H2O groups.

Chinleite-(Y), NaY(SO4)2·H2O, a new rare-earth sulfate mineral structurally related to bassanite

2017 ◽  
Vol 81 (4) ◽  
pp. 909-916 ◽  
Author(s):  
Anthony R. Kampf ◽  
Barbara P. Nash ◽  
Joe Marty
Keyword(s):  
Room Temperature ◽  
Three Dimensional ◽  
New Mineral ◽  
X Ray Diffraction ◽  
Calculated Density ◽  
Secondary Alteration ◽  
X Ray ◽  
Mohs Hardness ◽  
San Juan County ◽  
Bow Tie

AbstractThe new mineral chinleite-(Y) (IMA2016-017), NaY(SO4)2·H2O, was found in the Blue Lizard mine, San Juan County, Utah, USA, where it occurs as a secondary alteration phase. Chinleite-(Y) crystals are thin hexagonal {100} prisms (up to 0.3 mm long) with pyramidal terminations consisting of the forms {101} and {011}. Prisms are typically intergrown in divergent sprays, bow-tie aggregates or subparallel intergrowths. Crystals are colourless and transparent with a vitreous lustre. The streak is white and the mineral is nonfluorescent. The Mohs hardness is between 2½ and 3. Crystals are brittle with at least one good cleavage parallel to [001], probably {100}, and have splintery fracture. The mineral is slowly soluble in H2O at room temperature. The calculated density is 3.385 g cm–3. The mineralis optically uniaxial (+), with ω = 1.565(1) and ε = 1.603(1) (white light). Electron microprobe analyses yielded the empirical formula (Na0.507Ca0.285Y0.176)∑0.968(Y0.724Dy0.110Er0.053Gd0.037Ho0.021Yb0.013Nd0.014Eu0.005Sm0.008Ce0.010Pr0.003La0.002)∑1.000(SO4)2·H1.401O.The eight strongest powder X-ray diffraction lines are [dobs Å(I)(hkl)]: 6.01(59)(100), 5.43(63)(011), 3.457(46)(110), 3.010(100)(200), 2.826(95)(014), 2.1365(39)(006,122), 1.8493(67)(214) and 1.6901(28)(125,034). Chinleite-(Y) is trigonal, P3221,a = 6.890(2), c = 12.767(2) Å, V = 524.9(3) Å3 and Z = 3. The structure of chinleite-(Y) (R1 = 0.0444 for 303 Fo > 4σF), a three-dimensional framework, consisting of SO4 groups, irregular NaO8 polyhedra and YO9 distorted tricapped trigonal prisms, is similar to the structure of bassanite.

Kitagohaite, Pt7Cu, a new mineral from the Lubero region, North Kivu, Democratic Republic of the Congo

2014 ◽  
Vol 78 (3) ◽  
pp. 739-745 ◽  
Author(s):  
A. R. Cabral ◽  
R. Skála ◽  
A. Vymazalová ◽  
A. Kallistová ◽  
B. Lehmann ◽  
...  
Keyword(s):  
Crystal Structure ◽  
Vickers Hardness ◽  
Democratic Republic ◽  
Mean Value ◽  
New Mineral ◽  
Calculated Density ◽  
Reflected Light ◽  
Republic Of The Congo ◽  
Mohs Hardness ◽  
North Kivu

AbstractKitagohaite, ideally Pt7Cu, is a new mineral from the Lubero region of North Kivu, Democratic Republic of the Congo. The mineral occurs as alluvial grains that were recovered together with other Pt-rich intermetallic compounds and Au. Kitagohaite is opaque, greyish white and malleable and has a metallic lustre and a grey streak. In reflected light, kitagohaite is white and isotropic. The crystal structure of kitagohaite is cubic, space group Fmm, of the Ca7Ge type, with a = 7.7891(3) Å, V = 472.57(5) Å3 and Z = 4. The strongest diffraction lines [d in Å(I)(hkl)] are: 2.246 (100)(222), 1.948(8)(004), 1.377 (77)(044), 1.174(27)(622), 1.123 (31)(444) and 0.893 (13)(662). The Vickers hardness is 217 kg mm−2 (VHN100), which is equivalent to a Mohs hardness of 3½ and the calculated density is 19.958(2) g cm−3. Electron-microprobe analyses gave a mean value (n = 13) of 95.49 wt.% Pt and 4.78 wt.%Cu, which corresponds to Pt6.93Cu1.07 on the basis of eight atoms. The new mineral is named for the Kitagoha river, in the Lubero region.

Badakhshanite-(Y), Y2Mn4Al(Si2B7BeO24), a new mineral species of the perettiite group from a granite miarolic pegmatite in Eastern Pamir, the Gorno Badakhshan Autonomous Oblast, Tajikistan

2020 ◽  
Vol 58 (3) ◽  
pp. 381-394
Author(s):  
Leonid A. Pautov ◽  
Mirak A. Mirakov ◽  
Fernando Cámara ◽  
Elena Sokolova ◽  
Frank C. Hawthorne ◽  
...  
Keyword(s):  
Crystal Structure ◽  
Close Association ◽  
Coarse Grained ◽  
New Mineral ◽  
Orthorhombic Space Group ◽  
Calculated Density ◽  
Conchoidal Fracture ◽  
New Mineral Species ◽  
Mohs Hardness ◽  
Cation Sites

ABSTRACT Badakhshanite-(Y), ideally Y2Mn4Al(Si2B7BeO24), is a tetrahedral sheet-structure mineral found in the Dorozhny (Road) miarolitic granitic pegmatite within the Kukurt pegmatite field 45 km E of Murghab, Eastern Pamir, Gorno-Badakhshan Autonomous Oblast, Tajikistan. Badakhshanite-(Y) occurs in medium- to coarse-grained non-graphic albite-microcline-quartz pegmatites in close association with smoky quartz, Sc-bearing spessartine, Sc-bearing tusionite, and schorl. It often grows together with Sc-bearing tusionite and occurs as single columnar crystals ranging from 50 to 400 μm in length, as inclusions in spessartine and tourmaline, and rarely as crystals in blebs along boundaries between garnet, tourmaline, and quartz. Badakhshanite-(Y) is yellow brown and has a white streak and a vitreous luster. It is brittle, with a conchoidal fracture, Mohs hardness of 6.5–7, and calculated density of 4.41 g/cm. In thin section it is transparent and pale yellow, non-pleochroic, biaxial (–), with α = 1.805(2), βcalc = 1.827, γ = 1.835(3) (λ = 590 nm); 2V (meas.) = –60(10)°. Dispersion is weak, r &gt; v. Extinction is straight, elongation is negative. FTIR spectra show the absence of (OH) and H2O groups. Chemical analysis by electron microprobe using WDS (6 points), SIMS, and ICP-OES for B and Be gave SiO2 11.96, ThO2 0.12, Sm2O3 0.17, Gd2O3 0.30, Tb2O3 0.10, Dy2O3 0.73, Ho2O3 0.19, Er2O3 1.34, Tm2O3 0.54, Yb2O3 8.82, Lu2O3 2.32, Y2O3 16.60, Sc2O3 1.57, Al2O3 3.06, B2O3 22.06, FeO 0.94, MnO 23.33, CaO 0.58, BeO 2.84, total 97.57 wt.%.The empirical formula based on 24 O apfu is (Y1.21REE0.78Th0.01)Σ2(Mn3.47Y0.34Ca0.11Fe2+0.08)Σ4(Al0.63Sc0.24Fe2+0.06□0.07)Σ1[(Si2.10B6.69Be1.20)Σ9.99O24], where REE = (Yb0.47Lu0.12Dy0.04Er0.07Tm0.03 Ho0.01Gd0.02Sm0.01Tb0.01)Σ0.78. Badakhshanite-(Y) is orthorhombic, space group Pnma, a 12.852(1), b 4.5848(5), c 12.8539(8) Å, V 757.38(7) Å3, Z = 2. The crystal structure was refined to R1 = 4.31% based on 1431 unique [F &gt; 4σF] reflections. In the crystal structure of badakhshanite-(Y), a layer of tetrahedra parallel to (010) is composed of four different tetrahedrally coordinated sites: Si, B(1), B(2), and T (&lt;Si–O&gt; = 1.623 Å, &lt;B(1)–O&gt; = 1.485 Å, &lt;B(2)–O&gt; = 1.479 Å, &lt;T–O&gt; = 1.557 Å), which form four-, five-, and eight-membered rings, having the composition (Si2B7BeO24). Between the sheets of tetrahedra, there are three cation sites: M(1), M(2), and M(3) (&lt;M(1)–O&gt; = 2.346 Å, &lt;M(2)–O&gt; = 2.356 Å, &lt;M(3)–O&gt; = 2.016 Å) occupied by Y(REE), Mn2+(Y, Ca, Fe2+), and Al(Sc), respectively. The M(1,2) sites ideally give Y2Mn4apfu; the M(3) site ideally gives Al apfu. Badakhshanite-(Y) is an Al- and Be-analogue of perettiite-(Y).

Sign in / Sign up

Export Citation Format

Share Document