Bobcookite, NaAl(UO2)2(SO4)4·18H2O and wetherillite, Na2Mg(UO2)2(SO4)4·18H2O, two new uranyl sulfate minerals from the Blue Lizard mine, San Juan County, Utah, USA

2015 ◽  
Vol 79 (3) ◽  
pp. 695-714 ◽  
Author(s):  
Anthony R. Kampf ◽  
Jakub Plášil ◽  
Anatoly V. Kasatkin ◽  
Joe Marty

AbstractThe new minerals bobcookite (IMA 2014-030), NaAl(UO2)2(SO4)4·18H2O and wetherillite (IMA 2014-044), Na2Mg(UO2)2(SO4)4·18H2O, were found in the Blue Lizard mine, San Juan County, Utah, USA, where they occur together as secondary alteration phases in association with boyleite, chalcanthite, dietrichite, gypsum, hexahydrite, johannite, pickeringite and rozenite.Bobcookite descriptive details: lime green to greenish-yellow massive veins and columnar crystals; transparent; vitreous lustre; bright greenish-white fluorescence; pale greenish yellow streak; hardness (Mohs) 2½; brittle; conchoidal fracture; no cleavage; moderately hygroscopic; easily soluble in cold H2O; densitycalc= 2.669 g cm–3. Optically, biaxial (–), α = 1.501(1), β = 1.523(1), γ = 1.536(1) (white light); 2Vmeas.= 78(1)°; 2Vcalc.= 74°; dispersionr<v, moderate. Pleochroism:Xcolourless,Yvery pale yellow-green,Zpale yellow-green;X<Y<Z. EDS analyses yielded the empirical formula Na0.97Al1.09(U1.02O2)2(S0.98O4)4(H2O)18. Bobcookite is triclinic,P1,a= 7.7912(2),b= 10.5491(3),c= 11.2451(8) Å , α = 68.961(5), β = 70.909(5), γ = 87.139(6)°,V= 812.79(8) Å3andZ= 1. The structure (R1= 1.65% for 3580Fo> 4σF) contains [(UO2)(SO4)2(H2O)] chains linked by NaO4(H2O)2octahedra to form layers. Hydrogen bonds to insular Al(H2O)6 octahedra and isolated H2O groups hold the structure together. The mineral is named for Dr Robert (Bob) B. Cook of Auburn University, Alabama, USA.Wetherillite descriptive details: pale greenish-yellow blades; transparent; vitreous lustre; white streak; hardness (Mohs) 2; brittle; two cleavages, {101} perfect and {010} fair; conchoidal or curved fracture; easily soluble in cold H2O; densitycalc= 2.626 g cm–3. Optically, biaxial (+), α = 1.498(1), β = 1.508(1), γ = 1.519(1) (white light); 2Vmeas.= 88(1)°, 2Vcalc.= 87.9°; dispersion isr<v, distinct; optical orientation:Z=b,X∧a= 54° in obtuse β; pleochroism:Xcolourless,Ypale yellow-green,Zpale yellow-green;X<Y≈Z. EDS analyses yielded the empirical formula Na1.98(Mg0.58Zn0.24Cu0.11Fe0.092+)Σ1.02(U1.04O2)2(S0.98O4)4(H2O)18. Wetherillite is monoclinic,P21/c,a= 20.367(1),b= 6.8329(1),c= 12.903(3) Å, β = 107.879(10)°,V= 1709.0(5) Å3andZ= 2. The structure (R1= 1.39% for 3625Fo> 4σF) contains [(UO2)(SO4)2(H2O)] sheets parallel to {100}. Edge-sharing chains of Na(H2O)5O polyhedra link adjacent uranyl sulfate sheets forming a weakly bonded three-layer sandwich. The sandwich layers are linked to one another by hydrogen bonds through insular Mg(H2O)6octahedra and isolated H2O groups. The mineral is named for John Wetherill (1866–1944) and George W. Wetherill (1925–2006).

2015 ◽  
Vol 79 (5) ◽  
pp. 1123-1142 ◽  
Author(s):  
Anthony R. Kampf ◽  
Jakub Plášil ◽  
Anatoly V. Kasatkin ◽  
Joe Marty ◽  
Jiří Čejka

AbstractThe new minerals fermiite (IMA2014-068), Na4(UO2)(SO4)3·3H2O and oppenheimerite (IMA2014-073), Na2(UO2)(SO4)2·3H2O, were found in the Blue Lizard mine, San Juan County, Utah, USA, where they occur together as secondary alteration phases in association with blödite, bluelizardite, chalcanthite, epsomite, gypsum, hexahydrite, kröhnkite, manganoblödite, sideronatrite, tamarugite and wetherillite.Fermiite descriptive details: pale greenish-yellow prisms; transparent; vitreous lustre; bright greenishwhite fluorescence; white streak; hardness (Mohs) 2½; brittle; conchoidal fracture; no cleavage; slightly deliquescent; easily soluble in RT H2O; densitymeas = 3.23(2) g cm–3; densitycalc = 3.313 g cm–3. Optically, biaxial (+), α = 1.527(1), β = 1.534(1), γ = 1.567(1) (white light); 2Vmeas.= 51(1)°, 2Vcalc.= 50°; dispersionr<v, distinct. Pleochroism:X,Y= colourless,Z= pale greenish yellow;X=Y<Z. Energy dispersive spectroscopic (EDS) analyses yielded the empirical formula Na3.88(U1.05O2)(S0.99O4)3(H2O)3. Fermiite is orthorhombic,Pmn21,a= 11.8407(12),b= 7.8695(5),c= 15.3255(19) Å,V= 1428.0(2) Å3andZ= 4. The structure (R1= 2.21% for 1951Io> 3σI) contains [(UO2)(SO4)3] chains that are linked by bonds involving five different Na–O polyhedra to form a framework. The mineral is named for Italian-American theoretical and experimental physicist Dr. Enrico Fermi (1901–1954).Oppenheimerite descriptive details: pale greenish-yellow prisms; transparent; vitreous lustre; bright greenish-white fluorescence; white streak; hardness (Mohs) 2½; slightly sectile; three good cleavages, {110}, {011} and {101}; irregular fracture; slightly deliquescent; easily soluble in RT H2O; densitycalc = 3.360 g cm–3. Optically, biaxial (+), α = 1.537(1), β = 1.555(1), γ = 1.594(1) (white light); 2Vmeas.= 72(2)°, 2Vcalc.= 70°; dispersion isr>v, moderate, inclined; optical orientation:X≈ ⊥ {101},Z≈ [111]; pleochroism: X very pale greenish yellow, Y pale greenish yellow, Z greenish yellow; X < Y < Z. EDS analyses yielded the empirical formula Na1.94(U0.97O2)(S1.02O4)2(H2O)3. Oppenheimerite is triclinic,P1,a= 7.9576(6),b= 8.1952(6),c= 9.8051(7) Å, α = 65.967(5), β = 70.281(5), γ = 84.516(6)°,V= 549.10(8) Å3andZ= 2. The structure (R1= 3.07% for 2337Io> 3σI) contains [(UO2)(SO4)2(H2O)] chains that are linked by bonds involving two different Na–O polyhedra to form a framework. The mineral is named for American theoretical physicist Dr. J. Robert Oppenheimer (1904–1967).


2018 ◽  
Vol 82 (2) ◽  
pp. 401-411 ◽  
Author(s):  
Anthony R. Kampf ◽  
Jakub Plášil ◽  
Barbara P. Nash ◽  
Joe Marty

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.


2018 ◽  
Vol 82 (6) ◽  
pp. 1261-1275 ◽  
Author(s):  
Travis A. Olds ◽  
Jakub Plášil ◽  
Anthony R. Kampf ◽  
Peter C. Burns ◽  
Barbara P. Nash ◽  
...  

ABSTRACTRedcanyonite (IMA2016-082), (NH4)2Mn[(UO2)4O4(SO4)2](H2O)4, occurs underground in the Blue Lizard mine, Red Canyon, White Canyon district, San Juan County, Utah, USA. It occurs with natrozippeite, brochantite, devilline, posnjakite, johannite, gypsum, bobcookite, pickeringite, pentahydrite and the NH4-analogue of zippeite: ammoniozippeite. Redcanyonite occurs as radial aggregates of red–orange needles and blades individually reaching up to 0.2 mm long, with aggregates measuring up to 1 mm in diameter. Crystals are flattened on {010} and elongated along [100], exhibit perfect cleavage on {010}, and exhibit the forms {010}, {001}, {101} and {10$\bar{1}$}. Twinning is ubiquitous, by 180° rotation on [100]. Redcanyonite is translucent with a pale orange streak, is non-fluorescent, has a Mohs hardness of 2, and has brittle tenacity with uneven fracture. Optically, redcanyonite is biaxial (+), α = 1.725(3), β = 1.755(3), γ = 1.850(5) (white light); 2V (meas.) = 60(2)°, 2V (calc.) = 61.3°; and dispersion isr<v, very strong. Pleochroism is:X= orange,Y= yellow andZ= orange;Y<<X<Z. The optical orientation isX=b,Y≈c*,Z≈a. The empirical formula is (NH4)2.02(Mn0.49Cu0.09Zn0.06)Σ0.64H+0.72[(UO2)4O4(S0.99P0.01O4)2](H2O)4, based on 4 U and 24 O apfu. Redcanyonite is monoclinic,C2/m,a= 8.6572(17),b= 14.155(3),c= 8.8430(19) Å, β = 104.117(18)°,V= 1050.9(4) Å3andZ= 2. The structure was refined toR1= 0.0382 for 1079 reflections withIobs> 3σI. Uranyl oxo-sulfate sheets in redcanyonite adopt the well-known zippeite topology, which consists of zigzag chains of uranyl pentagonal bipyramids linked by sulfate tetrahedra to form sheets. The sheets are linked to each other through bonds to interlayer NH4+groups and octahedrally coordinated Mn2+, and by hydrogen bonds from H2O groups. Redcanyonite is named for Red Canyon in southeast Utah, USA.


2013 ◽  
Vol 77 (7) ◽  
pp. 2975-2988 ◽  
Author(s):  
J. Plášil ◽  
A. R. Kampf ◽  
A. V. Kasatkin ◽  
J. Marty ◽  
R. Škoda ◽  
...  

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.


2020 ◽  
Vol 84 (3) ◽  
pp. 435-443
Author(s):  
Anthony R. Kampf ◽  
Travis A. Olds ◽  
Jakub Plášil ◽  
Barbara P. Nash ◽  
Joe Marty

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.


2017 ◽  
Vol 81 (2) ◽  
pp. 273-285 ◽  
Author(s):  
Anthony R. Kampf ◽  
Jakub Plášil ◽  
Anatoly V. Kasatkin ◽  
Joe Marty ◽  
Jiří Čejka ◽  
...  

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.


2014 ◽  
Vol 78 (3) ◽  
pp. 639-649 ◽  
Author(s):  
A. R. Kampf ◽  
J. Plášil ◽  
A. V. Kasatkin ◽  
J. Marty

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.


2017 ◽  
Vol 81 (4) ◽  
pp. 895-907 ◽  
Author(s):  
Anthony R. Kampf ◽  
Jakub Plášil ◽  
Jiří Čejka ◽  
Joe Marty ◽  
Radek Škoda ◽  
...  

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.


2019 ◽  
Vol 83 (6) ◽  
pp. 799-808 ◽  
Author(s):  
Anthony R. Kampf ◽  
Travis A. Olds ◽  
Jakub Plášil ◽  
Barbara P. Nash ◽  
Joe Marty

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.


2019 ◽  
Vol 84 (2) ◽  
pp. 267-273
Author(s):  
Anthony R. Kampf ◽  
Barbara P. Nash ◽  
Arturo A. Molina Donoso

AbstractThe new mineral mauriziodiniite (IMA2019-036), NH4(As2O3)2I, was found at the Torrecillas mine, Iquique Province, Chile, where it is a secondary alteration phase associated with calcite, cuatrocapaite-(NH4), lavendulan, magnesiokoritnigite and torrecillasite on matrix consisting of native arsenic, arsenolite and pyrite. Mauriziodiniite occurs as hexagonal tablets up to ~300 μm in diameter. Crystals are colourless and transparent, with pearly to adamantine lustre and white streak. The Mohs hardness is ~1. Tablets are sectile and easily flexible, but not elastic. Fracture is curved, irregular and stepped. Cleavage is perfect on {001}. The calculated density is 3.916 g/cm3. Optically, mauriziodiniite is uniaxial (–) with ω = 2.07(calc) and ɛ = 1.770(5) (white light). The empirical formula, determined from electron microprobe analyses, is (NH4)0.94K0.03(As2O3)2I0.92Cl0.03. Mauriziodiniite is hexagonal, P6/mmm, a = 5.289(2), c = 9.317(2) Å, V = 225.68(18) Å3 and Z = 1. The structure, refined to R1 = 4.16% for 135 Io > 2σI reflections, contains three types of layers: (1) a planar neutral As2O3 (arsenite) sheet; (2) an NH4+ layer that links adjacent arsenite sheets via bonds to their O atoms; and (3) an I– layer that links adjacent arsenite sheets via bonds to their As atoms. The layer sequence is I–As2O3–NH4–As2O3–I. Mauriziodiniite is isostructural with lucabindiite and is structurally related to gajardoite, cuatrocapaite-(NH4), cuatrocapaite-(K) and torrecillasite.


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