New Mineral Names*,†

Barikaite*

D. Topa, E. Makovicky, H. Tajedin, H. Putz, and G. Zagler (2013) Barikaite, Pb₁₀Ag₃(Sb₈As₁₁)_Σ19S₄₀, a new member of the sartorite homologous series. Mineralogical Magazine, 77(7), 3039–3046.Topa D, Makovicky E, Tajedin H., Putz H, Zagler G. , (2013)"Barikaite, Pb₁₀Ag₃(Sb₈As₁₁)_Σ19S₄₀, a new member of the sartorite homologous series." Mineralogical Magazine, vol. 77, no. (7), p. 3039–3046.

D. Topa and E. Makovicky (2013) The crystal structure of barikaite. Mineralogical Magazine, 77(8), 3093–3104.Topa D, Makovicky E. , (2013)"The crystal structure of barikaite" Mineralogical Magazine, vol. 77, no. (8), p. 3093–3104.

Barikaite (IMA 2012-055), ideally Pb₁₀Ag₃(Sb₈As₁₁)_Σ19S₄₀, is a new antimony-containing species of the sartorite homologous series discovered at the Barika Au-Ag deposit, Azarbaijan Province of Western Iran. The lens-like deposit ~150 m long and up to 20 m thick consists of massive banded pyrite and barite ores accompanied by locally developed silica bands. Pyrite, sphalerite, galena, tetrahedrite-tennantite, and stibnite were deposited during the synvolcanogenic hydrothermal activity of Cretaceous age. Fractures host veinlets with Ag-As-Sb-Pb-rich sulfosalts: tetrahedrite-tennantite, stephanite, pyrargyrite, trechmannite, smithite, miargyrite, andorite, geocronite, seligmannite, guettardite and realgar and Ag-Au alloys. Barikaite is always found in association with guettardite in quartz veins hosting irregular thin veinlets and nests of sulfosalts in a mass of quartz and baryte. The mineral occurs as anhedral grains with no twinning. It has been replaced by guettardite, resulting in corroded remnants of what was a solid barikaite aggregate. The mineral is grayish black, opaque, metallic with dark gray streak. It is brittle with irregular fracture and no cleavage or parting. The microhardness VHN₅₀ = 200 (192–212) kg/mm² corresponds to ~3 of Mohs scale. The density could not be measured due to admixture of guettardite; D_calc = 5.34 g/cm³. In reflected light barikaite is grayish white with distinct pleochroism from white to dark gray. Internal reflections are absent. Anisotropism is distinct with rotation tints in shades of gray. The reflectance spectrum was measured in air between 400 and 700 nm with 20 nm interval. The values for COM wavelengths are [R_min, R_max % (nm)]: 37.0, 39.3 (470); 34.1, 36.9 (546); 33.1, 36.2 (589); 31.3, 34.1 (650). The average of 5 electron probe WDS analyses is [wt% (range)]: Ag 5.80 (4.93–5.87), Pb 35.77 (35.50–39.21), Sb 18.33 (17.49–18.37), As 15.64 (15.18–15.77), T1 0.15(0.07–0.22), S 24.00 (23.65–23.92), total 99.69. The empirical formula on the basis of 32Me + 40S = 72 apfu is Pb_9.31Ag_2.90T1_0.04(Sb_8.12 As_11.26)_Σ19.36S_40.37. The single crystal X-ray study shows barikaite is monoclinic with space group P2₁/n and unit-cell parameters a = 8.533(1), b = 8.075(1), c = 24.828(2) Å, β = 99.077(6)°, V = 1689.2 ų; Z = 1. The X-ray powder data was not be obtained due to paucity of pure material. The strongest lines of the calculated X-ray powder diffraction pattern [d Å (I%; hkl)] are: 3.835 (63; 022), 3.646 (100; 016), 3.441 (60; 212), 3.408 (62; 214), 2.972 (66; 216), 2.769 (91; 222), 2.752 (78; 424), 2.133 (54; 402). The crystal structure of barikaite contains 8 cation sites and 10 anion sites. Four of the cation sites have mixed occupancies: the split sites As2-Sb2, As3-Sb3, Ag5-As5, and the site Me6 with three cations involved. Two sites, Pb1 and Pb2, have tricapped trigonal prismatic coordination and alternate along a. They form zigzag walls parallel to (001). There are 3 distinct [100] columns of alternating cations, As1-(As,Sb)2, Sb4-(As,Sb)3, (As,Ag)5-(Pb,Sb)6, which together form trapezoidally configured single (013) layers. These layers aggregate into tightly bonded double layers, separated by lone electron pair micelles. The predominantly As- and Sb-occupied sites are in a chess-board order. Barikaite is a member of the sartorite homologous series. The empirical values of homolog order N derived from the chemical analyses are in fair agreement with the crystallographic value N = 4. Barikaite is a close homeotype of rathite and less closely related to dufrénoysite (distinct, pure arsenian N = 4 members) and completes the spectrum of Sb-rich members of the sartorite homologous series. The mineral is named for the type locality. The holotype specimen is deposited in the Natural History Museum Vienna, Austria. D.B.

Deveroite-(Ce)*

A. Guastoni, F. Nestola, P. Gentile, F. Zorzi, M. Alvaro, A. Lanza, L. Peruzzo, M. Schiazza, and N.M. Casati (2013) Deveroite-(Ce): a new REE-oxalate from Mount Cervandone, Devero Valley, Western-Central Alps, Italy. Mineralogical Magazine, 77(7), 3019–3026.Guastoni A, Nestola F, Gentile P, Zorzi F, Alvaro M, Lanza A, Peruzzo L, Schiazza M, Casati NM. , (2013)"Deveroite-(Ce): a new REE-oxalate from Mount Cervandone, Devero Valley, Western-Central Alps, Italy" Mineralogical Magazine, vol. 77, no. (7), p. 3019–3026.

Deveroite-(Ce) (IMA 2013-003), ideally Ce₂(C₂O₄)₃•10H₂O, is a new mineral and the third natural oxalate discovered in the alpine fissures of Mount Cervandone, overlooking the Devero Valley, Piedmont, Italy. The area is characterized by swarms of pegmatite dikes crosscutting metamorphic rocks and hosted by leucocratic gneisses. These dikes containing Ba-Y-REE-As minerals [aeschynite-(Y), agardite-(Y), Nb-anatase, As-fergusonite-beta-(Y), cervandonite-(Ce), chernovite-(Y), crichtonitesenaite, fluorite, gadolinite-(Y), monazite-(Ce), paraniite-(Y), synchysite-(Ce), and xenotime-(Y)] as well as meter-long quartz veins crosscutting pegmatite dikes. Deveroite-(Ce) crystallization related to circulation of meteoric waters enriched with oxalic acid. A source of oxalate is provided by incomplete oxidation of organic material such as decaying plant remains. A source of REE is provided by the hosting mineral, cervandonite-(Ce), and not completely described REE-arsenosilicate. Deveroite-(Ce) occurs only on crystals of cervandonite-(Ce) and is associated with agardite-(Ce), asbecasite, cafarsite, K-feldspar, muscovite, and quartz. It forms sprays of colorless elongated tabular or acicular prisms up to ~50 μm. It has a white streak, vitreous luster and a perfect cleavage along {010}. The mineral is brittle with Mohs hardness of ~2–2½. Density was not measured due to the size of crystals; D_calc = 2.352 g/cm³. Fluorescence was not observed. Deveroite-(Ce) is non-pleochroic, optically biaxial (−) with 2V of ~77°, and the extinction angle (Y^c) of ~27°. No twinning was observed. The refractive indexes were not measured but proposed to be very close to that of synthetic La₂(C₂O₄)₃•10H₂O: α = 1.473, β = 1.548, γ = 1.601°. The average of 11 electron probe EDS analyses [wt%, (range)] is CaO 0.34 (0.25–0.44), C₂O₃ (by stoichiometry) 29.7, Y₂O₃ 1.66 (1.19–2.04), La₂O₃ 7.29 (6.60–8.40), Ce₂O₃ 22.8 (22.03–24.28), Pr₂O₃ 2.53 (2.10–2.88), Nd₂O₃ 7.53 (7.14–7.90), Sm₂O₃ 0.24 (0.13–0.43), PbO₂ 1.24 (1.42–2.53), ThO₂ 0.29 (0.22–0.35), UO₂ 1.05 (0.86–1.19), H₂O (by stoichiometry) 24.8; total 99.47. The empirical formula based on 22 O pfu is (Ce_1.01Nd_0.33La_0.32Pr_0.11Y_0.11Sm_0.01Pb_0.04U_0.03Th_0.01Ca_0.04)_Σ2.01(C₂O₄)_Σ2.99•9.99H₂O. The strongest lines of the X-ray powder diffraction pattern [d Å (I%; hkl)] are: 10.266 (100; 100), 4.816 (35; 211), 3.415 (28; 300), 5.125 (25; 200), 4.988 (23; 111). The unit-cell parameters refined from powder data are: a = 11.2725(9), b = 9.6109(9), c = 10.346(1) Å , β = 114.539(7)°, V = 1019.621 ų. The small size of the crystal (13 μm × 3 μm × 1 μm) did not allow to obtain reliable structural data, but allow to find the deveroite-(Ce) is monoclinic, space group P2₁/c, a = 11.240(8), b = 9.635(11), c = 10.339(12) Å, β = 114.41(10)°, V = 1019.6 ų; Z = 2. Deveroite-(Ce) is named for the type locality at Devero valley and Devero Natural Park. The holotype material is deposited in the Museum of Mineralogy, Department of Geosciences at the University of Padova, Italy. D.B.

Hizenite-(Y)*

Y. Takai and S. Uehara (2013) Hizenite-(Y), Ca₂Y₆(CO₃)₁₁•14H₂O, a new mineral in alkali olivine basalt from Mitsukoshi, Karatsu, Saga Prefecture, Japan. Journal of Mineralogical and Petrological Sciences, 108(3), 161–165.Takai Y, Uehara S. , (2013)"Hizenite-(Y), Ca₂Y₆(CO₃)₁₁•14H₂O, a new mineral in alkali olivine basalt from Mitsukoshi, Karatsu, Saga Prefecture, Japan" Journal of Mineralogical and Petrological Sciences, vol. 108, no. (3), p. 161–165.

Hizenite-(Y) (IMA 2011-030), ideally Ca₂Y₆(CO₃)₁₁•14H₂O, is a new mineral discovered at Mitsukoshi, Karatsu, Saga Prefecture, Japan. It occurs in small cavities in Higashimatsuura Neogen alkali olivine basalt closely associating with lokkaite-(Y), tengerite-(Y), and kimuraite-(Y). The mineral forms platy crystals up to 50 × 0.2 μm forming radial spherical aggregates up to 1 cm. Hizenite-(Y) is white with a white streak and vitreous to silky luster. The cleavage is perfect on {001}. The hardness, optical properties and density were not measured; D_calc = 2.98 g/cm³. The average of 5 electron probe EDS analyses [wt% (range)] is Y₂O₃ 27.61 (26.20–29.60), La₂O₃ 1.11 (0.95–1.41), Pr₂O₃ 0.65 (0–0.89), Nd₂O₃ 5.80 (4.69–6.72), Sm₂O₃ 1.68 (1.04–1.97), Eu₂O₃ 0.73 (0–1.56), Gd₂O₃ 3.82 (2.85–4.70), Tb₂O₃ 0.24 (0–0.79), Dy₂O₃ 3.10 (2.75–3.54), Ho₂O₃ 0.47 (0–0.93), Er₂O₃ 1.58 (1.02–1.83), Tm₂O₃ 0.04 (0–0.22), Yb₂O₃ 0.10 (0–0.51), CaO 5.93 (5.38–6.42), CO₂ 29.55 (28.78–30.32), H₂O 15.03 (14.85–15.21), total 97.44. The contents of H₂O and CO₂ were obtained by a CHN analyzer. The empirical formula based on 47 O pfu is Ca_1.76(Y_4.08Nd_0.58Gd_0.35Dy_0.28Sm_0.16Er_0.14La_0.11Pr_0.07Eu_0.07 Ho_0.04Tb_0.02Yb_0.01)_Σ5.91(CO₃)_11.2•13.9H₂O. The strongest lines of the X-ray powder diffraction pattern [d Å (I%; hkl)] are: 15.57 (20; 004), 10.63 (100; 006), 6.384 (77; 0.0.10), 3.962 (51; 0.0.16),3.821 (27; 029, 1.0.13), 2.060 (23; 306, 0.4.13). The orthorhombic unit-cell parameters refined from the powder data are: a = 6.295(1), b = 9.089(2), c = 63.49(1) Å, V = 3632(1) ų, Z = 4. Single-crystal X-ray diffraction study was not performed due to the small crystal size. Unit-cell data were obtained using TEM electron diffraction and then refined using XRD data. Hizenite-(Y) structure model suggests the alternating of Y-corrugated sheets and Ca-H₂O layers along c axes. The structure is related to that of kimuraite-(Y), lokkaite-(Y), and tengerite-(Y). The name is for “Hizen” the old name of the mineral type locality between 7th and 16th century. The type specimen is deposited in Kitakyushu Museum of Natural History and Human History, Kitakyushu, Japan. D.B.

Kobyashevite*

I.V. Pekov, N.V. Zubkova, V.O. Yapaskurt, D.I. Belakovskiy, N.V. Chukanov, A.V. Kasatkin, A.M. Kuznetsov, and D.Yu. Pushcharovsky (2013) Kobyashevite, Cu₅(SO₄)₂(OH)₆·4H₂O, a new devilline-group mineral from the Vishnevye Mountains, South Urals, Russia. Mineralogy and Petrology, 107, 201–210.Pekov IV, Zubkova NV, Yapaskurt VO, Belakovskiy DI, Chukanov NV, Kasatkin AV, Kuznetsov AM, Pushcharovsky D Yu. , (2013)"Kobyashevite, Cu₅(SO₄)₂(OH)₆·4H₂O, a new devilline-group mineral from the Vishnevye Mountains, South Urals, Russia" Mineralogy and Petrology, vol. 107, p. 201–210.

Kobyashevite (IMA 2011-066), ideally Cu₅(SO₄)₂(OH)₆·4H₂O, is a new mineral from the Kapital’naya mine (pyrochlore ore mine operated for Na and Ta) at the Vishnevye Mountains, South Urals, Russia. It occurs as a supergene mineral in cavities of calcite-quartz vein with minor pyrite and chalcopyrite, cutting fenites of the Vishnevogorsky alkaline complex. Kobyashevite forms elongated crystals up to 0.1 mm, rarely 0.2 mm, which show a prismatic habit and are typically curved or split, divergent on calcite and quartz surfaces. Crystals are transparent, bluish-green to turquoise colored, with bluish-green streak and a vitreous luster. It does not fluoresce on UV or cathode rays. Mohs hardness is ∼3. D_calc = 3.155 g/cm³. Kobyashevite is optically biaxial (−), with α = 1.602(4), β = 1.666(5), and γ = 1.679(5)° (light not reported; λ = 589 nm), 2V_meas = 50(10)° and 2V_calc = 47°. Dispersion is r < v, strong; Zis close to the crystal elongation direction. Pleochroism is medium Z> Y> X, changing only intensity of the bluish-green tint. The average of 4 electron probe EDS analyses [wt% (range)] is: CuO 57.72 (56.7–58.4), ZnO 0.09 (0.0–0.2), FeO 0.28 (0.2–0.4), SO₃ 23.52 (22.2–24.7), H₂O (by difference), total 100.00. The empirical formula based on 18 O apfu is: Cu_4.96Fe_0.03Zn_0.01S_2.01O_8.04(OH)_5.96·4H₂O. The strongest lines of the X-ray powder diffraction pattern [dÅ (I%; hkl)] are: 10.84 (100; 010), 5.399 (40; 020), 5.178 (12; 110), 3.590 (16; 030), 2.691 (16; 201, 040, 002), 2.653 (12; 041, 022), 2.583 (12; 211, 201, 211), 2.425 (12; 032, 211, 131). Unit-cell parameters refined from the powder data are: a = 6.08(4), b = 11.07(8), c = 5.51(4) Å, α = 102.8(2), β = 92.4(2), γ = 92.5(2)°, V = 360(2) ų. X-ray single-crystal diffraction study on a crystal fragment 150 × 80 × 10 μm shows the mineral is triclinic, space group P1; a = 7.8702(7), b = 15.8081(6), c = 6.6389(14) Å, V = 821.06(19) ų; Z = 8. The crystal structure of kobyashevite [refined to R₁ = 0.0399 for 1218 unique I > 2σ(I) reflections] is almost identical to its synthetic equivalent and contains [Cu₄(SO₄)₂(OH)₆] corrugated layers coplanar to ac. Each layer is built up of a cationic sheet of edge-sharing Cu-centered octahedra. Layers are linked by Jahn-Teller highly distorted [CuO₂(H₂O)₄] octahedra which share two vertices corresponding to the longest distances with SO₄ tetrahedra. The structure of kobyashevite can be also considered as a combination of brucite-like octahedral layers linked by trimers formed by one Cu-centered octahedron and two SO₄ tetrahedra. Hydrogen positions were observed in the Fourier difference and added to the model and refined with soft constrains. The number of O–H-stretching bands observed in the IR spectrum (8) coincides with the number of different hydrogen bonds. Kobyashevite is a devilline-group mineral and is named in memory of the Russian mineralogist Yuriy Stepanovich Kobyashev (1935–2009), a specialist on mineralogy of the Urals. The type specimen of kobyashevite is deposited in the Fersman Mineralogical Museum of the Russian Academy of Sciences, Moscow, Russia. F.C.

Leverettite*

A.R. Kampf, M.J. Sciberras, P.A. Williams, M. Dini, and A.A. Molina Donoso (2013) Leverettite from the Torrecillas mine, Iquique Province, Chile: the Co-analogue of herbertsmithite. Mineralogical Magazine, 77(7), 3047–3054.Kampf AR, Sciberras MJ, Williams PA, Dini M, Donoso AA Molina. , (2013)"Leverettite from the Torrecillas mine, Iquique Province, Chile: the Co-analogue of herbertsmithite" Mineralogical Magazine, vol. 77(7), p. 3047–3054.

Leverettite (IMA 2013-011), ideally Cu₃CoCl₂(OH)₆, is a new mineral from Torrecillas mine, Salar Grande, Iquique Province, Chile. It occurs as a supergene alteration phase in association with akaganeite, anhydrite, chalcophanite, goethite, halite, manganite, pyrite, quartz, and todorokite, and forms steep rhombohedra to 1mm with prominent {101} modified by {001}, with infrequent V-shaped twins by reflection on {102}, and finger-like, parallel-stacked growths parallel to c. Crystals are transparent, deep green colored with green streak and a vitreous luster. Crystals have a perfect cleavage on {101}, conchoidal fracture and are brittle. Mohs hardness is ∼3; D_meas = 3.64(2) g/cm³ (by flotation in Clerici solution), D_calc = 3.709 g/cm³. Leverettite is optically uniaxial (−), with ω and ε > 1.8 and exhibits pleochroism with O (bluish green) > E (slightly yellowish green). The average electron probe WDS analyses [wt% (range)] is: CuO 62.80 (56.44–67.65), CoO 7.49 (5.64–9.85), NiO 1.23 (0.51–2.77), MnO 2.72 (0.78–3.68), MgO 0.06 (0.00–0.12), Cl 15.40 (14.58–15.80), H₂O 12.57 (calculated on the basis of O+Cl = 8 apfu), –Cl=O 3.47, total 98.80. The empirical formula based on O+Cl = 8 apfu is: Cu₃(Co_0.43Cu_0.40Mn_0.17N_i0.07Mg_0.01)_Σ1.08Cl_1.87O_6.13H₆. The strongest lines of the X-ray powder diffraction pattern [d Å (I%; hkl)] are: 5.469 (90; 101), 4.701 (18; 003), 2.905 (22; 021), 2.766 (100; 113), 2.269 (66; 024), 1.822 (26; 033), 1.711 (33; 220), 1.383 (23; 128). Unit-cell parameters refined from the powder data are: a = 6.8383(9), c = 14.081(2) Å, V = 570.2 ų. X-ray single-crystal diffraction study on a crystal fragment 150 × 100 × 90 μm shows the mineral is trigonal, space group R3m; a = 6.8436(6), c = 14.0637(10) Å, V = 570.42(8) ų; Z = 3. The crystal structure of leverettite [refined to R₁ = 0.0226 for unique I > 2σ(I) reflections] is analogous to the structure of herbertsmithite and gillardite. Optically and crystallographically it would be difficult to distinguish a crystal of leverettite from the other analogs (herbertsmithite, haydeeite, and gillardite) without recourse to chemical analyses. Leverettite extends upon the known substitution series for naturally occurring members of the paratacamite group. The mineral is named in honor of Peter Leverett (b. 1944), professor of Chemistry at the University of Western Sydney, in recognition of his contributions to research and teaching in chemistry and chemical geology. Four type specimens are retained in the Natural History Museum of Los Angeles County, Los Angeles, California, U.S.A. F.C.

Magnesiokoritnigite*

A.R. Kampf, B.P. Nash, M. Dini, and A.A. Molina Donoso (2013) Magnesiokoritnigite, Mg(AsO₃OH)•H₂O, from the Torrecillas mine, Iquique Province, Chile: the Mg-analogue of koritnigite. Mineralogical Magazine, 77(8), 3081–3092.Kampf AR, Nash BP, Dini M, Donoso AA Molina. , (2013)"Magnesiokoritnigite, Mg(AsO₃OH)•H₂O, from the Torrecillas mine, Iquique Province, Chile: the Mg-analogue of koritnigite" Mineralogical Magazine, vol. 77, no. (8), p. 3081–3092.

Magnesiokoritnigite (IMA 2013-049), ideally Mg(AsO₃OH)• H₂O, is a new mineral from Torrecillas mine, Salar Grande, Iquique Province, Chile. It occurs as a secondary alteration phase in association with anhydrite, chudobaite, halite, lavendulan, quartz, and scorodite, and forms colorless to pale-pink 2 mm long laths elongated on [001] and flattened on {010}, as well as in dense deep-pink intergrowths. Crystals are transparent, with vitreous luster and white streak. They are brittle, with conchoidal fracture and perfect cleavage on {101}. Mohs hardness is ∼3; D_meas = 2.95(3) (by flotation in Clerici solution), D_calc = 2.935 g/cm³. Magnesiokoritnigite is optically biaxial (+), with α = 1.579(1), β = 1.586(1), γ = 1.620(1)° (white light), 2V_meas = 50(2)°, and 2V_calc = 50°. Dispersion is r < v, medium and the optical orientation is Y ≈ b; Z ^ c = 36° in obtuse β. The mineral is slowly soluble in concentrated HCl or HNO₃ and very slowly soluble in concentrated H₂SO₄. The average of 9 electron probe WDS analyses [wt% (range)] is: MgO 19.88 (19.27–20.54), CaO 0.36 (0.12–0.72), MnO 0.90 (0.40–1.46), CuO 1.03 (0.74–1.24), As₂O₅ 58.02 (57.40–58.74), H₂O 15.11 [calculated on the basis of (Mg+Ca+Mn+Cu) = 1, charge balance and 5 O apfu], total 95.30. The empirical formula based on 5 O apfu is: (Mg_0.94Cu_0.03Mn_0.02Ca_0.01)_Σ1.00As_0.96O₅H_3.19. The strongest lines of the X-ray powder diffraction pattern [dÅ (I%; hkl)] are: 7.96 (100; 020), 4.80 (54; 101), 3.791 (85; 210,210,131,131), 3.242 (56; 012,221,012), 3.157 (92; 211,230,230), 3.021 (61; 141,141,221,221), 2.798 (41; 032,032) and 1.908(43; multiple). Unit-cell parameters refined from the powder data are: a = 7.868(7), b = 15.838(7), c = 6.626(7) Å, α = 91.064(18), β = 96.394(17), γ = 90.02(3)°, and V = 820.4 ų. X-ray single-crystal diffraction study on a crystal fragment 150 × 80 × 10 μm shows the mineral is triclinic, space group P1; a = 7.8702(7), b = 15.8081(6), c = 6.6389(14) Å, V = 821.06 ų; Z = 8. The crystal structure of magnesiokoritnigite [refined to R₁ = 0.0574 for 2360 unique F > 4σ(F) reflections] is isostructural with those of koritnigite and cobaltkoritnigite and consists of zigzag edge-sharing chains of MgO₅(H₂O) octahedra running parallel to [101] that are joined by corner-sharing with AsO₃(OH) tetrahedra to form sheets parallel to {010}. Sheets are linked in the [010] direction only by hydrogen bonds. The mineral is named as the Mg analog of koritnigite. One holotype and two cotype specimens are deposited in the Natural History Museum of Los Angeles County, Los Angeles, California, U.S.A. F.C.

Mössbauerite*

J.-M.R. Génin, S.J. Mills, A.G. Christy, O. Guérin, A.J. Herbillon,E. Kuzmann, G. Ona-Nguema, C. Ruby, and C. Upadhyay (2014) Mössbauerite, Fe63+ O4(OH)8[CO3]⋅3H2O, the fully oxidized ‘green rust’ mineral from Mont Saint-Michel Bay, France. Mineralogical Magazine, 78(2), 447–465.Génin J-MR, Mills SJ, Christy AG, Guérin O, Herbillon AJ, Kuzmann E, Ona-Nguema G, Ruby C, Upadhyay C. , (2014)"Mössbauerite, Fe63+ O4(OH)8[CO3]⋅3H2O, the fully oxidized ‘green rust’ mineral from Mont Saint-Michel Bay, France" Mineralogical Magazine, vol. 78, no. (2), p. 447–465.

Mössbauerite (IMA 2012-049), ideally Fe6 − 6x2+Fe6x3+ O4x(OH)12 − 4x[CO3]⋅3H2O, is a new mineral found in intertidal gleys from Mont Saint-Michel Bay, France, where it occurs intimately intergrown with trébeurdenite along with quartz, feldspars, and clay minerals as a consequence of the oxidation of the other members of the fougèrite group. It forms micrometer-scale platelets in gleys with restricted access to atmospheric O and decomposes rapidly when exposed to air. Mössbauerite has not been identified visually but individual crystallites in pure synthetic material are <0.2 μm wide and show distinct hexagonal outlines in TEM images, where the forms {001}, {100}, or {110} can be discerned. Pure synthetic mössbauerite is orange in color. Detailed optical and other physical properties could not be determined because of the small platelet size and instability. Mohs hardness is probably 2–3. D_calc = 2.950 g/cm³. It was not possible to analyze natural mössbauerite directly, as it is inevitably intergrown with the closely related mineral trébeurdenite. Chemical analyses of areas approximately 0.5 mm × 0.4 mm on a pressed chip of the gley yielded totals of 55–64%. Synchrotron X-ray data indicate that the natural material is a nanoscale intergrowth of 2T and 3T polytypes; the latter probably has the 3T₇ stacking sequence. The corresponding maximum possible space group symmetries are P3m1 and P3m1, respectively. The strongest lines of the X-ray powder diffraction pattern of synthetic mössbauerite-3T [dÅ (I%; hkl)] are: 22.79 (80; 001), 7.471 (81; 003), 2.806 (5; 008), 2.663 (5; 010), 2.557 (38; 012), 2.263 (16; 015) and 1.482 (5; 00.15). Unit-cell parameters refined from the powder data are: a = 3.032(17), c = 22.258(4) Å, and V = 177.17 ų. Mössbauer spectroscopy at 78 K indicates that two distinct Fe³⁺ environments exist in a 2:1 ratio, interpreted to be ordered within each layer, but without the development of a three-dimensional super lattice. Mössbauerite undergoes gradual magnetic ordering at 70–80 K to a ferromagnetic state. It is inferred that there is short-range coupling of interlayer carbonate anions with respect to the octahedral layers while a 2D long-range order of carbonates in interlayers remains unchanged. Mössbauerite is a layered double hydroxide (LDH) mineral, with a structure in which Fe³⁺ cations in the center of octahedra with (OH^– and O²⁻) anions lying at vertices share edges to form a stacking of brucite-like layers with a net positive charge, with carbonate and water in the interlayers. Carbonate “green rust” with varying overall oxidation ratio corresponds to intimate mixtures of three fixed-composition phases with x = Fe³⁺/(Fe²⁺+Fe³⁺) = 1/3, 2/3, and 1. The formulas of these phases all correspond to Fe6 − 6x2+Fe6x3+ O4x(OH)12 − 4x[CO3]⋅3H2O and correspond to fougèrite (x = 1/3), trébeurdenite (x = 2/3), and mössbauerite (x = 1), which form the fougèrite group of the hydrotalcite supergroup. The mineral is named after Rudolf Ludwig Mössbauer (1928–2011) who discovered the resonance of γ rays that bears his name, for which he was awarded the 1961 Nobel Prize in physics. Without this technique, the very existence of this mineral in gleysoils and the true nature of the “green rust” compounds could not be understood. One wet holotype sample sealed in a glass jar is preserved in the collections of Museum Victoria, Melbourne, Australia. Other samples are now hosted in the Mineralogical Museum of Eötvös University (Budapest, Hungary), the Mineralogical Collection of the École des Mines (Paris, France), and the Collection of the Université Catholique de Louvain-la Neuve (Belgium). F.C.

Shimazakiite* (4M and 4O Polytypes)

I. Kusachi, S. Kobayashi, Y. Takeuchi, Y. Nakamuta, T. Nagase, K. Yokoyama, K. Momma, R. Miyawaki, M. Shigeoka, and S. Matsubara (2013) Shimazakiite-4M and shimazakiite-4O, Ca₂B₂O₅, two polytypes of a new mineral from Fuka, Okayama Prefecture, Japan. Mineralogical Magazine, 77(1), 93–105.Kusachi I, Kobayashi S, Takeuchi Y, Nakamuta Y, Nagase T, Yokoyama K, Momma K, Miyawaki R, Shigeoka M, Matsubara S. , (2013)"Shimazakiite-4M and shimazakiite-4O, Ca₂B₂O₅, two polytypes of a new mineral from Fuka, Okayama Prefecture, Japan" Mineralogical Magazine, vol. 77, no. (1), p. 93–105.

The new mineral shimazakiite (IMA 2010-085a), ideally Ca₂B₂O₅, was discovered in two polytypes: shimazakiite-4M and shimazakiite-4O in an irregular vein in crystalline limestone near gehlenite-spurrite skarns at Fuka mine, Okayama Prefecture, Japan. The mineral is closely associated with takedaite and calcite formed during the post-metasomatic stage of primary skarn mineralization. Associated minerals include sibirskite, parasibirskite, olshanskyite, nifontovite, and an uncharacterized hydrous calcium borate. Gehlenite and spurrite occur as pyrometasomatic alteration products of the limestone. Shimazakiite forms aggregates up to 3 mm where shimazakiite-4M tends to occur in nanometer-sized twin lamellae and shimazakiite-4O in micrometer-sized lamellae. The new mineral is grayish white with white streak and vitreous luster. It is brittle with an uneven fracture and with no observed cleavage. The microhardness VHN₅₀ = 549 (516–566) for shimazakiite-4M and 598 (480–701) kg/mm² for shimazakiite-4O, corresponding to ~4 of the Mohs scale. For shimazakiite-4O D_meas = 2.81(2) g/cm³ (by flotation in Clerici solution) while for shimazakiite-4M it was not measured due to the paucity of pure material; D_calc= 2.78 and 2.77 g/cm³ respectively. Both polytypes are transparent in the transmitted light with no pleochroism. The mineral is biaxial (−), α = 1.586(2), β = 1.650(2), γ = 1.667(2)°, 2V_calc = 53° for shimazakiite-4M and α = 1.584(2), β = 1.648(2), γ = 1.670(2)°, 2Vcalc = 54.88° for shimazakiite-4O (λ = 589 nm). No fluorescence was observed. The IR spectrum of shimazakiite-4M has an OH-stretching band at 3440 cm⁻¹, and strong bands 1360, 1170, 1000, 730, 680, 620, and 320 cm^–1 due to the borate group. The means of electron probe WDS analyses (28 for 4M and 25 for 4O poly-types) are respectively [wt% (range)]: CaO 61.09 (60.51–61.46) and 61.30 (60.85–61.50), B₂O₃ 36.39 (34.61–37.76) and 36.51 (35.61–37.35), H₂O (by stoichiometry) 1.19 and 1.20; total 98.67 and 99.01. The empirical formulas on the basis of 5 O apfu are Ca₂B_1.92O_4.76(OH)_0.24 for both polytypes. Chemically shimazakiite varies from almost no H₂O and no B deficiency compositions to those with a B deficiency and corresponding H₂O content. The low analytical total for the B-deficient material suggests substitution of 3(OH)^–for (BO₃)^3–. Therefore the formula can be written as Ca₂B_2–xO_5–3x(OH)_3x, with x = 0–0.2. The strongest lines of the powder-diffraction pattern obtained using Gandolfi camera with d = 114.6 mm are [dÅ (I%; hkl)]: 6.03 (27; 011), 3.84 (30; 014), 3.02 (84; 022), 2.92 (100; 104), 2.81 (56; 104), 2.76 (32; 113), 1.880 (32; 118,126,126,118) for shimazakiite-4M and 6.03 (19; 011), 3.84 (33; 014), 3.02 (42; 022), 2.86 (100; 104), 2.79 (29; 113), 1.903 (44; 126,118) for shimazakiite-4O. The single-crystal X-ray diffraction studies on a crystals of 0.2 × 0.1 × 0.03 mm show for shimazakiite-4M, the space group P2₁/c, a = 3.5485(12), b = 6.352(2), c = 19.254(6) Å, = 92.393(13)°, V = 433.6 ų, Z = 4. For shimazakiite-4O, the space group P2₁2₁2₁, a = 3.55645(8), b = 6.35194(15), c = 19.2534(5) Å, V = 434.941 ų. The crystal structure of shimazakiite [refined to R₁ = 0.1273 and 0.0142 for 843 and 995 unique I > 2σ(I) reflections respectively for 4M and 4O polytypes] consists of a layer containing B2O₅ units (two near-coplanar triangular corner-sharing BO₃ groups) and sixfold- and sevenfold-coordinated Ca atoms. Different sequences in the c direction of four layers are observed in the polytypes. The name is for Hidehiko Shimazaki (b. 1939), Emeritus Professor at the University of Tokyo, in recognition of his outstanding contribution to skarn mineralogy. The type specimen of shimazakiite has been deposited in the collections of the National Museum of Nature and Science, Tokyo, Japan. D.B.

Takanawaite-(Y)*

D. Nishio-Hamane, T. Minakawa, and Y. Ohgoshi (2013) Takanawaite-(Y), a new mineral of the M-type polymorph with Y(Ta,Nb)O₄ from Takanawa Mountain, Ehime Prefecture, Japan. Journal of Mineralogical and Petrological Sciences, 108(6), 335–344.Nishio-Hamane D, Minakawa T, Ohgoshi Y. , (2013)"Takanawaite-(Y), a new mineral of the M-type polymorph with Y(Ta,Nb)O₄ from Takanawa Mountain, Ehime Prefecture, Japan" Journal of Mineralogical and Petrological Sciences, vol. 108, no. 6, p. 335–344.

Takanawaite-(Y) (IMA 2011-099), a new natural mono-clinic polymorph of Y(Ta,Nb)O₄ was discovered at Takanawa Mountain, Ehime Prefecture, Japan. It was found in allanitefergusonite-zircon-biotite pegmatites within the granites. The new mineral is closely associated with gadolinite-(Y) and zircon at the boundary between quartz and feldspar. Other associated minerals include muscovite and allanite-(Ce). Takanawaite-(Y) forms dark brown submetamict single crystals of a tabular habit up to 5 mm or radial aggregates of fine crystals. The internal cracks in the crystals are filled with Ca- and Ta-rich oxide. The crystals are of {010} habit with {100} and {001}forms and are striated along [101] on {010} faces. The fracture is conchoidal and no cleavage observed (result of metamictization). The Mohs hardness is 5½; D_calc = 6.97 g/cm³. No other physical properties given. The average of 5 electron probe EDS analyses [wt% (range)] is: Y₂O₃ 27.07 (26.46–27.67), Gd₂O₃ 1.16 (0.36–2.50), Dy₂O₃ 4.64 (3.60–5.50), Yb₂O₃ 2.90 (1.40–4.50), UO₂ 2.77 (2.40–3.31), TiO₂ 0.51 (0.37–0.68), FeO 0.39 (0.26–0.58), Nb₂O₅ 19.22 (18.43–19.63), Ta₂O₅ 40.49 (40.10–41.27), total 99.15. The empirical formula of takanawaite-(Y) based on 4 O apfu is (Y_0.75Dy_0.08Yb_0.05Gd_0.02U_0.03Ti_0.02Fe_0.02)_Σ0.97(Ta_0.57Nb_0.45)_Σ1.02O₄. The Ta/(Ta+Nb) ratio varies between 0.55 and 0.57. The X-ray powder diffraction pattern before the heating is extremely broad with a few intensities at ~3.0, 2.6, 1.8, and 1.6 Å considered to be a traces of M phase. After the heating in air at 600 °C for 24 h, the powder turned to reddish-brown. The reflections appeared in XRD pattern were indexed in tetragonal unit-cell, space group P4₂/nmc, a=3.658(4), c = 5.393(9) Å [T′ phase which differs from formanite-(Y)]. After the heating in air at 1000 °C for 24 h, the powder turned to dull pale green and XRD pattern became consistent (after subtracting peaks of calciotantite and microlite) with monoclinic (M) phase, space group I2/a, unit-cell parameters a = 5.3182(8), b = 10.9583 (13), c = 5.0595 (7) Å, β = 94.993(14)°, V = 293.74(7) ų, Z = 4 (D_calc = 6.97 g/cm³). The strongest lines of that powder XRD pattern [d Å, (I%; hkl)] are 3.133 (100; 121), 2.953 (85; 121), 2.739 (29; 040), 2.649 (21; 200), 1.912 (24; 202), 1.905 (39; 240), 1.855 (26; 042), 1.568 (19; 242). Another monoclinic (M′) phase equal to the mineral iwashiroite-(Y) did not appear during the experiment. After a consecutive 24 h reheating at 600 °C, the Tʹ phase did not reappear indicating its metastability and XRD pattern showed only the presence of M phase. The results of X-ray powder diffraction study were confirmed by TEM electron diffraction. Several monoclinic phases crystallized after heating metamict YTaO₄ at 900 to 1000 °C were previously described as formanite-(Y): from Siberia, Russia (Kornetsova and Kazakova, 1964); from type locality of formanite-(Y) (Lima de Faria 1964); from amazonite pegmatite of Western Keivy, Kola Peninsula, Russia (Voloshin et al. 2003). The XRD pattern and composition for the last one show the similarity to takanawaite-(Y) as defined here. The mineral was named after its type locality. The type specimen is deposited at the National Museum of Nature and Science, Tokyo, Japan. D.B.

Comment: The relationships between natural Y(Ta,Nb)O₄ polymorphs are still not completely clear. Formanite-(Y) described as tetragonal (Palache et al. 1944) was later mentioned as monoclinic (see above) and also described by Shi and Peng (1981, not cited in the abstracted paper) from Gan Xian, Jiangxi Province, China, with unit-cell parameters and space group identical (heated and unheated) to a later described iwashiroite-(Y). The space group for an orthorhombic(?) yttrotantalite-(Y) remains unknown. The study of type specimens is required to clear. The case is particularly tangled since in most cases the natural material is metamictic.