ALBERT

Description: 〈div data-abstract-type="normal"〉〈p〉Magnesioleydetite (IMA2017-063), Mg(UO〈span〉2〈/span〉)(SO〈span〉4〈/span〉)〈span〉2〈/span〉·11H〈span〉2〈/span〉O, and straβmannite (IMA2017-086), Al(UO〈span〉2〈/span〉)(SO〈span〉4〈/span〉)〈span〉2〈/span〉F·16H〈span〉2〈/span〉O, are two new minerals from mines in Red Canyon, San Juan County, Utah, USA. Magnesioleydetite occurs in the Markey mine and straβmannite occurs in both the Markey and Green Lizard mines. Both minerals are secondary phases found in efflorescent crusts on the surfaces of mine walls. Magnesioleydetite occurs in irregular aggregates (to ~0.5 mm) of blades (to ~0.2 mm) exhibiting the following properties: transparent to translucent; pale green–yellow colour; vitreous lustre; white streak; non-fluorescent; brittle; Mohs hardness ≈ 2; irregular fracture; one perfect cleavage on {001}; and calculated density = 2.463 g/cm〈span〉3〈/span〉. Straβmannite occurs in irregular aggregates (to ~0.5 mm) of equant crystals (to ~0.2 mm) exhibiting the following properties: transparent; light yellow–green colour; vitreous to greasy lustre; nearly white streak; bright greenish-blue fluorescence; somewhat brittle, Mohs hardness ≈ 1½; irregular fracture; one good cleavage on {001}; measured and calculated densities of 2.20(2) and 2.173 g/cm〈span〉3〈/span〉, respectively; optically biaxial (–); α = 1.477(2), β = 1.485(2) and γ = 1.489(2) (white light); 2V〈span〉meas.〈/span〉 = 72(2)°; dispersion 〈span〉r〈/span〉 〉 〈span〉v〈/span〉 (slight); orientation 〈span〉Y〈/span〉 = 〈span〉b〈/span〉, 〈span〉X〈/span〉 ∧ 〈span〉c〈/span〉 = 20° (in obtuse β); pleochroism with 〈span〉X〈/span〉 = nearly colourless, 〈span〉Y〈/span〉 = pale green–yellow and 〈span〉Z〈/span〉 = light green–yellow (〈span〉X〈/span〉 Y Z). The empirical formulas for magnesioleydetite and straβmannite are (Mg〈span〉0.56〈/span〉Fe〈span〉0.26〈/span〉Zn〈span〉0.11〈/span〉Mn〈span〉0.01〈/span〉)〈span〉Σ0.94〈/span〉(U〈span〉0.99〈/span〉O〈span〉2〈/span〉)(S〈span〉1.015〈/span〉O〈span〉4〈/span〉)〈span〉2〈/span〉·11H〈span〉2〈/span〉O and Al〈span〉1.00〈/span〉Na〈span〉0.16〈/span〉(U〈span〉0.99〈/span〉O〈span〉2〈/span〉)(S〈span〉1.00〈/span〉O〈span〉4〈/span〉)〈span〉2〈/span〉[F〈span〉0.58〈/span〉(OH)〈span〉0.42〈/span〉]·16H〈span〉2〈/span〉O, respectively. Magnesioleydetite is monoclinic, 〈span〉C〈/span〉2/〈span〉c〈/span〉, 〈span〉a〈/span〉 = 11.3513(3), 〈span〉b〈/span〉 = 7.7310(2), 〈span〉c〈/span〉 = 21.7957(15) Å, β = 102.387(7)°, 〈span〉V〈/span〉 = 1868.19(16) Å〈span〉3〈/span〉 and 〈span〉Z〈/span〉 = 4. Straβmannite is monoclinic, 〈span〉C〈/span〉2/〈span〉c〈/span〉, 〈span〉a〈/span〉 = 11.0187(5), 〈span〉b〈/span〉 = 8.3284(3), 〈span〉c〈/span〉 = 26.6727(19) Å, β = 97.426(7)°, 〈span〉V〈/span〉 = 2427.2(2) and 〈span〉Z〈/span〉 = 4. The structures of magnesioleydetite (〈span〉R〈/span〉〈span〉1〈/span〉 = 0.016 for 2040 〈span〉I〈/span〉 〉 2σ〈span〉I〈/span〉 reflections) and straβmannite (〈span〉R〈/span〉〈span〉1〈/span〉 = 0.0343 for 2220 〈span〉I〈/span〉 〉 2σ〈span〉I〈/span〉 reflections) each contain uranyl-sulfate sheets based on the protasite-anion topology.〈/p〉〈/div〉

Description: 〈div data-abstract-type="normal"〉〈p〉The new mineral ammoniomathesiusite (NH〈span〉4〈/span〉)〈span〉5〈/span〉(UO〈span〉2〈/span〉)〈span〉4〈/span〉(SO〈span〉4〈/span〉)〈span〉4〈/span〉(VO〈span〉5〈/span〉)·4H〈span〉2〈/span〉O, was found in the Burro mine, San Miguel County, Utah, USA, where it occurs as a secondary phase on asphaltum/quartz matrix in association with ammoniozippeite, gypsum, jarosite and natrozippeite. The mineral forms pale yellow to greenish-yellow prisms, up to ~0.3 mm long, with pale-yellow streak and bright yellow–green fluorescence. Crystals are transparent and have vitreous lustre. The mineral is brittle, with Mohs hardness of 2½, stepped fracture and two cleavages: excellent on {110} and good on {001}. The calculated density is 3.672 g/cm〈span〉3〈/span〉. Ammoniomathesiusite is optically uniaxial (–) with ω = 1.653(2) and ε = 1.609(2) (white light). Pleochroism is: 〈span〉O〈/span〉 = green-yellow, 〈span〉E〈/span〉 = colourless; 〈span〉O〈/span〉 〉 〈span〉E〈/span〉. Electron microprobe analyses yielded the empirical formula [(NH〈span〉4〈/span〉)〈span〉4.75〈/span〉(UO〈span〉2〈/span〉)〈span〉4〈/span〉(SO〈span〉4〈/span〉)〈span〉4〈/span〉(VO〈span〉5〈/span〉)·4(H〈span〉2.07〈/span〉O). The five strongest powder X-ray diffraction lines are [〈span〉d〈/span〉〈span〉obs〈/span〉 Å(〈span〉I〈/span〉)(〈span〉hkl〈/span〉)]: 10.57(46)(110), 7.10(62)(001), 6.41(100)(101), 3.340(35)(240) and 3.226(44)(141). Ammoniomathesiusite is tetragonal, 〈span〉P〈/span〉4/〈span〉n〈/span〉 with 〈span〉a〈/span〉 = 14.9405(9), 〈span〉c〈/span〉 = 7.1020(5) Å, 〈span〉V〈/span〉 = 1585.3(2) Å〈span〉3〈/span〉 and 〈span〉Z〈/span〉 = 2. The structure of ammoniomathesiusite (〈span〉R〈/span〉〈span〉1〈/span〉 = 0.0218 for 3427 〈span〉I〈/span〉 〉 2σ〈span〉I〈/span〉) contains heteropolyhedral sheets based on [(UO〈span〉2〈/span〉)〈span〉4〈/span〉(SO〈span〉4〈/span〉)〈span〉4〈/span〉(VO〈span〉5〈/span〉)]〈span〉5–〈/span〉 clusters. The structure is identical to that of mathesiusite, with 〈span〉〈span〉〈img data-mimesubtype="gif" data-type="simple" src="http://static.cambridge.org/resource/id/urn:cambridge.org:id:binary:20190313104343836-0311:S0026461X18001123:S0026461X18001123_inline1.gif"〉 〈span data-mathjax-type="texmath"〉 〈/span〉 〈/span〉〈/span〉 in place of K〈span〉+〈/span〉.〈/p〉〈/div〉

Description: Rakovanite, Na3{H3[V10O28]}{middle dot}15H2O, is a new mineral species from the Sunday and the West Sunday mines, Slick Rock district, San Miguel County, Colorado, USA; the mineral is the natural analog of the previously synthesized phase. Rakovanite is orange, with an orange-yellow streak. Crystals of rakovanite are up to 1 mm in maximum dimension and vary in habit from blocky to prismatic on [100]. The mineral is transparent, with a subadamantine luster; it does not fluoresce in long- or short-wave ultraviolet radiation. Rakovanite displays brittle tenacity, and has a Mohs hardness of 1. No cleavage or parting was observed, and the mineral displays a conchoidal fracture. The density calculated from the ideal formula and the single-crystal cell data is 2.407 g cm-3. Rakovanite is biaxial (+), with {alpha}589nm = 1.776(5), {beta}589nm = 1.803(5), {gamma}589nm = 1.910(6). The measured values of 2V are: 2Vz540nm = 58(1); 2Vz589nm = 56(1); 2Vz650nm = 53(1){degrees}. Dispersion is r 〈 v, strong, parallel; orientation: X = b; Z / c = 8{degrees} in obtuse {beta}. The pleochroic scheme in rakovanite is: X light yellow, Y orangish yellow, Z yellowish orange, Z 〉 Y 〉 X. Its chemical composition was obtained by electron-probe microanalysis and the crystal-structure refinement; the empirical formula (V = 10 apfu) is (Na2.90K0.07Ca0.01Al0.01){sum}2.99{H2.98[V10O28]}{middle dot}15H2O, and the simplified formula is Na3{H3[V10O28]}{middle dot}15H2O. Rakovanite is monoclinic, space group P21/n, with a 12.0248(17), b 17.121(3), c 18.140(3) A, {beta} 106.242(8){degrees}, and Z = 4; the strongest four lines in the powder-diffraction pattern [d in A(I)(hkl)] are: 11.270(100)([IMG]f1.gif" ALT="Formula" BORDER="0"〉01), 7.696(81)(021), 8.709(78)(002), and 6.892(63)(120). The atomic arrangement of rakovanite has been refined to R1 = 0.0383; the structural unit in the phase is formed of a triply-protonated decavanadate polyanion, {H3[V10O28]}. The structural units are linked by the interstitial complexes, the (Na3{middle dot}15H2O) contents of which balance the +3 charges of the decavanadate polyanion with a NaO4(H2O)2 group, a Na2(H2O)10 dimer, and three H2O molecules that do not bond to the interstitial cations.

Description: 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 71º. Indices of refraction for postite are α 1.727(3), β 1.733(3), and γ1.745(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 (Mg0.97Na0.06Ca0.04Sr0.01K0.01)∑1.09Al1.94 [(OH)1.92(H2O)0.08]‡”2.00 (V10O28)·27H2O. The simplified structural formula of postite is Mg(H2O)6Al2(OH)2(H2O)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 [Al2(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 [Al2(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).

Description: 〈div data-abstract-type="normal"〉〈p〉The new mineral feynmanite, Na(UO〈span〉2〈/span〉)(SO〈span〉4〈/span〉)(OH)·3.5H〈span〉2〈/span〉O, 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〈span〉–3〈/span〉. Crystals are thin needles or blades, flattened on {010} and elongate on [100], exhibiting the forms {010}, {001}, {101} and {10〈span〉〈span〉〈img data-mimesubtype="gif" data-type="simple" src="http://static.cambridge.org/resource/id/urn:cambridge.org:id:binary:20190522072108342-0385:S0026461X18001172:S0026461X18001172_inline1.gif"〉 〈span data-mathjax-type="texmath"〉 〈/span〉 〈/span〉〈/span〉}, 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); 2V〈span〉meas.〈/span〉 = 62(2)°; no dispersion; and optical orientation: 〈span〉X〈/span〉 = 〈span〉b〈/span〉, 〈span〉Y〈/span〉 ≈ 〈span〉a,〈/span〉〈span〉Z〈/span〉 ≈ 〈span〉c〈/span〉. It is weakly pleochroic: 〈span〉X〈/span〉 = colourless, 〈span〉Y〈/span〉 = very pale green yellow and 〈span〉Z〈/span〉 = pale green yellow (〈span〉X〈/span〉 Y Z). Electron microprobe analyses (WDS mode) provided (Na〈span〉0.84〈/span〉Fe〈span〉0.01〈/span〉)(U〈span〉1.01〈/span〉O〈span〉2〈/span〉)(S〈span〉1.01〈/span〉O〈span〉4〈/span〉)(OH)·3.5H〈span〉2〈/span〉O. The five strongest powder X-ray diffraction lines are [〈span〉d〈/span〉〈span〉obs〈/span〉 Å(〈span〉I〈/span〉)(〈span〉hkl〈/span〉)]: 8.37(100)(010), 6.37(33)(〈span〉〈span〉〈img data-mimesubtype="gif" data-type="simple" src="http://static.cambridge.org/resource/id/urn:cambridge.org:id:binary:20190522072108342-0385:S0026461X18001172:S0026461X18001172_inline2.gif"〉 〈span data-mathjax-type="texmath"〉 〈/span〉 〈/span〉〈/span〉01,101), 5.07(27)(〈span〉〈span〉〈img data-mimesubtype="gif" data-type="simple" src="http://static.cambridge.org/resource/id/urn:cambridge.org:id:binary:20190522072108342-0385:S0026461X18001172:S0026461X18001172_inline3.gif"〉 〈span data-mathjax-type="texmath"〉 〈/span〉 〈/span〉〈/span〉11,111), 4.053(46)(004,021) and 3.578(34)(120). Feynmanite is monoclinic, has space group 〈span〉P〈/span〉2/〈span〉n〈/span〉, 〈span〉a〈/span〉 = 6.927(3), 〈span〉b〈/span〉 = 8.355(4), 〈span〉c〈/span〉 = 16.210(7) Å, β = 90.543(4)°, 〈span〉V〈/span〉 = 938.1(7) Å〈span〉3〈/span〉 and 〈span〉Z〈/span〉 = 4. The structure of feynmanite (〈span〉R〈/span〉〈span〉1〈/span〉 = 0.0371 for 1879 〈span〉I〈/span〉〈span〉o〈/span〉 〉 2σ〈span〉I〈/span〉) contains edge-sharing pairs of pentagonal bipyramids that are linked by sharing corners with SO〈span〉4〈/span〉 groups, yielding a [(UO〈span〉2〈/span〉)〈span〉2〈/span〉(SO〈span〉4〈/span〉)〈span〉2〈/span〉(OH)〈span〉2〈/span〉]〈span〉2–〈/span〉 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.〈/p〉〈/div〉

Description: Gunterite, Na4(H2O)16(H2V10O28)·6H2O, is a new mineral species from the West Sunday mine, Slick Rock district, San Miguel County, Colorado, U.S.A. Crystals of gunterite are tabular on {001} and generally stacked into elongate curved multiple crystals up to 0.5 mm in maximum dimension; the crystals are orange-yellow, with a yellow streak. The mineral displays a subadamantine luster, and is transparent; it does not fluoresce in short- or long-range ultraviolet radiation. Gunterite has a hardness of about 1, a brittle tenacity, and an irregular fracture; no cleavage or parting was observed. The density calculated from the empirical formula using the single-crystal cell data is 2.398 g cm-3. Gunterite is biaxial (+), with a 1.735(5), ß 1.770(5) and ? 1.825(5); 2V is equal to 78° (white light). The dispersion v 〈 r is strong and parallel. Optical orientation; X = b, Y ˜ c; pleochroism: X yellow, Y orange, Z yellow; Y 〉 X 〉 Z. Gunterite is soluble in water at room temperature. Electronprobe microanalysis and the crystal-structure solution provided the empirical formula (V + Al = 10 apfu): (Na3.20K0.02Ca0.87)?4.09[H1.06(V9.99Al0.01)?10O28]·22H2O. The simplified formula of gunterite is Na4(H2O)16(H2V10O28)·6H2O. There is extensive substitution of Ca for Na in gunterite, yielding a structural formula of (Na4-xCax)?4.00(H2O)16(H2-xV10O28)·6H2O; the average value of x from the chemical analyses is 0.85. Gunterite is monoclinic, C2/m, with a 19.848(2), b 10.1889(11), c 13.1184(15) Å, ß 130.187(9)°, V 2026.6(4) Å3, and Z = 2. The strongest four lines in the diffraction pattern [d in Å(I)hkl] are: 10.01(100)2¯01,001, 8.44(72)110, 8.09(46)1¯11, and 2.997(29)3¯31,401. The atomic arrangement of gunterite was refined to R1 = 0.0632. The structural unit is a doubly-protonated decavanadate polyanion, {H2[V10O28]}. The interstitial units linking the structural units contain two Na polyhedra; the Na2 polyhedron is split into two partially occupied sites that are 0.76 Å apart, and significant Ca occupies that site. Several of the H2O molecules in the interstitial complex are disordered. The mineral is named in honor of Mickey E. Gunter, Professor of Mineralogy at the University of Idaho.

Description: We report on the discovery, description and solution of the structure of a new member of the pascoite family of minerals, hughesite, from the Sunday mine, Gypsum Valley, San Miguel County, Slick Rock District, Colorado, USA (38°4’19” N, 108°48’15” W). Orange to golden orange crystals of hughesite occur in efflorescent crusts, averaging 2 mm thick, on the sandstone walls of mine workings and in rock fractures. Hughesite forms through the oxidation of corvusite, (Na,Ca,K)1–x (V5+,V4+,Fe2+)8O28•4H2O, and montrosite, (V3+,Fe2+,V4+)O(OH), the primary vanadium oxide phases present, as they react with acidic, oxidizing groundwater. Crystals vary in habit, including blocky, spear-shaped, and platy, with one good cleavage on (001). Crystals are transparent to translucent with a subadamantine luster, and upon partial dehydration, they become opaque. Hughesite is biaxial (–), with a 1.698(5), ß 1.740(5), ? 1.770(5), and the measured 2V589nm is 84(2)°. It exhibits a strong r 〉 v dispersion, and is pleochroic with X = Y light golden yellow, and Z dark golden yellow. Its absorption is characterized by Z 〉 Y = X. Electron-probe microanalysis and the crystal-structure solution provided the empirical formula Na2.99Al1.05(V10O28)•22 H2O (based upon V = 10 apfu). The ideal formula of hughesite is Na3AlV10O28•22H2O. The density calculated from the empirical formula using the single-crystal cell data is 2.29 g/cm3. Hughesite is triclinic, space group P1¯, with a 8.668(4), b 10.295(4), c 12.908(5), a 105.826(9), ß 97.899(9), ? 103.385(9)°, V 1053.0(8) Å3, and Z = 1. The strongest four lines in the powder-diffraction pattern [d in Å(I)hkl]: are 12.24(100)001¯, 8.25(38)100, 9.50(30)01¯0, and 8.99(28)01¯1. The crystal structure, refined to R1 = 0.0496, consists of two components, the structural unit, which contains the decavanadate (V10O28)6- polyanion, and the fully hydrated interstitial complex, composed of two separate components, a Na3(OH2)12O2 trimer with two distinct cation sites, and a Al(OH2)6 monomer.

Description: 〈div data-abstract-type="normal"〉〈p〉The new mineral markeyite (IMA2016-090), Ca〈span〉9〈/span〉(UO〈span〉2〈/span〉)〈span〉4〈/span〉(CO〈span〉3〈/span〉)〈span〉13〈/span〉·28H〈span〉2〈/span〉O, was found in the Markey mine, San Juan County, Utah, USA, where it occurs as a secondary phase on asphaltum in association with calcite, gypsum and natrozippeite. The mineral is pale yellowish-green with white streak and fluoresces bright bluish white under a 405 nm laser. Crystals are transparent and have vitreous to pearly lustre. It is brittle, with Mohs hardness 1½ to 2, irregular fracture and three cleavages: perfect on {001}; good on {100} and {010}. The measured density is 2.68 g cm〈span〉–3〈/span〉. Crystals are blades, flattened on {001} and elongate on [010], exhibiting the forms {100}, {010}, {001}, {110}, {101}, {011} and {111}. Markeyite is optically biaxial (–) with α = 1.538(2), β = 1.542(2) and γ = 1.545(2) (white light); the measured 2V is 81(2)°; the dispersion is 〈span〉r〈/span〉 v (weak); the optical orientation is 〈span〉X〈/span〉 = 〈span〉c〈/span〉, 〈span〉Y〈/span〉 = 〈span〉b〈/span〉, 〈span〉Z〈/span〉 = 〈span〉a〈/span〉; and pleochroism is 〈span〉X〈/span〉 = light greenish yellow, 〈span〉Y〈/span〉 and 〈span〉Z〈/span〉 = light yellow (〈span〉X〈/span〉 〉 〈span〉Y〈/span〉 ≈ 〈span〉Z〈/span〉). Electron microprobe analyses (energy-dispersive spectroscopy mode) yielded CaO 18.60, UO〈span〉3〈/span〉 42.90, CO〈span〉2〈/span〉 21.30 (calc.) and H〈span〉2〈/span〉O 18.78 (calc.), total 101.58 wt.% and the empirical formula Ca〈span〉8.91〈/span〉(U〈span〉1.01〈/span〉O〈span〉2〈/span〉)〈span〉4〈/span〉(CO〈span〉3〈/span〉)〈span〉13〈/span〉·28H〈span〉2〈/span〉O. The six strongest powder X-ray diffraction lines are [〈span〉d〈/span〉〈span〉obs〈/span〉 Å(〈span〉I〈/span〉)(〈span〉hkl〈/span〉)]: 10.12(69)(001), 6.41(91)(220,121), 5.43(100)(221), 5.07(33)(301,002,131), 4.104(37)(401,141) and 3.984(34)(222). Markeyite is orthorhombic, 〈span〉Pmmn〈/span〉, 〈span〉a〈/span〉 = 17.9688(13), 〈span〉b〈/span〉 = 18.4705(6), 〈span〉c〈/span〉 = 10.1136(4) Å, 〈span〉V〈/span〉 = 3356.6(3) Å〈span〉3〈/span〉 and 〈span〉Z〈/span〉 = 2. The structure of markeyite (〈span〉R〈/span〉〈span〉1〈/span〉 = 0.0435 for 3427 〈span〉F〈/span〉〈span〉o〈/span〉 〉 4σ〈span〉F〈/span〉) contains uranyl tricarbonate clusters (UTC) that are linked by Ca–O polyhedra forming thick corrugated heteropolyhedral layers. Included within the layers is an additional disordered CO〈span〉3〈/span〉 group linking the Ca–O polyhedra. The layers are linked to one another and to interlayer H〈span〉2〈/span〉O groups only via hydrogen bonds. The structure bears some similarities to that of liebigite.〈/p〉〈/div〉

Description: 〈div data-abstract-type="normal"〉〈p〉Redcanyonite (IMA2016-082), (NH〈span〉4〈/span〉)〈span〉2〈/span〉Mn[(UO〈span〉2〈/span〉)〈span〉4〈/span〉O〈span〉4〈/span〉(SO〈span〉4〈/span〉)〈span〉2〈/span〉](H〈span〉2〈/span〉O)〈span〉4〈/span〉, 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 NH〈span〉4〈/span〉-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〈span〉〈span〉〈img data-mimesubtype="gif" data-type="simple" src="http://static.cambridge.org/resource/id/urn:cambridge.org:id:binary:20190128104130349-0707:S0026461X18001007:S0026461X18001007_inline1.gif"〉 〈span data-mathjax-type="texmath"〉 〈/span〉 〈/span〉〈/span〉}. 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 is 〈span〉r〈/span〉 v, very strong. Pleochroism is: 〈span〉X〈/span〉 = orange, 〈span〉Y〈/span〉 = yellow and 〈span〉Z〈/span〉 = orange; 〈span〉Y〈/span〉 X Z. The optical orientation is 〈span〉X〈/span〉 = 〈span〉b〈/span〉, 〈span〉Y〈/span〉 ≈ 〈span〉c〈/span〉*, 〈span〉Z〈/span〉 ≈ 〈span〉a〈/span〉. The empirical formula is (NH〈span〉4〈/span〉)〈span〉2.02〈/span〉(Mn〈span〉0.49〈/span〉Cu〈span〉0.09〈/span〉Zn〈span〉0.06〈/span〉)〈span〉Σ0.64〈/span〉H〈span〉+〈/span〉〈span〉0.72〈/span〉[(UO〈span〉2〈/span〉)〈span〉4〈/span〉O〈span〉4〈/span〉(S〈span〉0.99〈/span〉P〈span〉0.01〈/span〉O〈span〉4〈/span〉)〈span〉2〈/span〉](H〈span〉2〈/span〉O)〈span〉4〈/span〉, based on 4 U and 24 O apfu. Redcanyonite is monoclinic, 〈span〉C〈/span〉2〈span〉/m〈/span〉, 〈span〉a〈/span〉 = 8.6572(17), 〈span〉b〈/span〉 = 14.155(3), 〈span〉c〈/span〉 = 8.8430(19) Å, β = 104.117(18)°, 〈span〉V〈/span〉 = 1050.9(4) Å〈span〉3〈/span〉 and 〈span〉Z〈/span〉 = 2. The structure was refined to 〈span〉R〈/span〉〈span〉1〈/span〉 = 0.0382 for 1079 reflections with 〈span〉I〈/span〉〈span〉obs〈/span〉 〉 3σ〈span〉I〈/span〉. 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 NH〈span〉4〈/span〉〈span〉+〈/span〉 groups and octahedrally coordinated Mn〈span〉2+〈/span〉, and by hydrogen bonds from H〈span〉2〈/span〉O groups. Redcanyonite is named for Red Canyon in southeast Utah, USA.〈/p〉〈/div〉

Description: Magnesioleydetite (IMA2017-063), Mg(UO2)(SO4)2·11H2O, and straβmannite (IMA2017-086), Al(UO2)(SO4)2F·16H2O, are two new minerals from mines in Red Canyon, San Juan County, Utah, USA. Magnesioleydetite occurs in the Markey mine and straβmannite occurs in both the Markey and Green Lizard mines. Both minerals are secondary phases found in efflorescent crusts on the surfaces of mine walls. Magnesioleydetite occurs in irregular aggregates (to ~0.5 mm) of blades (to ~0.2 mm) exhibiting the following properties: transparent to translucent; pale green–yellow colour; vitreous lustre; white streak; non-fluorescent; brittle; Mohs hardness ≈ 2; irregular fracture; one perfect cleavage on {001}; and calculated density = 2.463 g/cm3. Straβmannite occurs in irregular aggregates (to ~0.5 mm) of equant crystals (to ~0.2 mm) exhibiting the following properties: transparent; light yellow–green colour; vitreous to greasy lustre; nearly white streak; bright greenish-blue fluorescence; somewhat brittle, Mohs hardness ≈ 1½; irregular fracture; one good cleavage on {001}; measured and calculated densities of 2.20(2) and 2.173 g/cm3, respectively; optically biaxial (–); α = 1.477(2), β = 1.485(2) and γ = 1.489(2) (white light); 2Vmeas. = 72(2)°; dispersion r > v (slight); orientation Y = b, X ∧ c = 20° (in obtuse β); pleochroism with X = nearly colourless, Y = pale green–yellow and Z = light green–yellow (X 〈 Y 〈 Z). The empirical formulas for magnesioleydetite and straβmannite are (Mg0.56Fe0.26Zn0.11Mn0.01)Σ0.94(U0.99O2)(S1.015O4)2·11H2O and Al1.00Na0.16(U0.99O2)(S1.00O4)2[F0.58(OH)0.42]·16H2O, respectively. Magnesioleydetite is monoclinic, C2/c, a = 11.3513(3), b = 7.7310(2), c = 21.7957(15) Å, β = 102.387(7)°, V = 1868.19(16) Å3 and Z = 4. Straβmannite is monoclinic, C2/c, a = 11.0187(5), b = 8.3284(3), c = 26.6727(19) Å, β = 97.426(7)°, V = 2427.2(2) and Z = 4. The structures of magnesioleydetite (R1 = 0.016 for 2040 I > 2σI reflections) and straβmannite (R1 = 0.0343 for 2220 I > 2σI reflections) each contain uranyl-sulfate sheets based on the protasite-anion topology.