New Mineral Names*,†

New Mineral Names*,†

American Mineralogist, Volume 100, pages 1649–1654, 2015 New Mineral Names*,† DMITRIY I. BELAKOVSKIY1 AND OLIVIER C. GAGNE2 1Fersman Mineralogical Museum, Russian Academy of Sciences, Leninskiy Prospekt 18 korp. 2, Moscow 119071, Russia 2Department of Geological Sciences, University of Manitoba, Winnipeg, Manitoba R3T 2N2, Canada IN THIS ISSUE This New Mineral Names has entries for 10 new minerals, including debattistiite, evdokimovite, ferdowsiite, karpovite, kolskyite, markhininite, protochabournéite, raberite, shulamitite, and vendidaite. DEBATTISTIITE* for 795 unique I > 2σ(I) reflections] corner-sharing As(S,Te)3 A. Guastoni, L. Bindi, and F. Nestola (2012) Debattistiite, pyramids form three-membered distorted rings linked by Ag atoms in triangular or distorted tetrahedral coordination. Certain Ag9Hg0.5As6S12Te2, a new Te-bearing sulfosalt from Len- genbach quarry, Binn valley, Switzerland: description and features of that linkage are similar to those in the structures of crystal structure. Mineralogical Magazine, 76(3), 743–750. trechmannite and minerals of pearceite–polybasite group. Of the seven anion positions, one is almost fully occupied by Te (Te0.93S0.07). The Hg atom is in a nearly perfect linear coordination Debattistiite (IMA 2011-098), ideally Ag9Hg0.5As6S12Te2, is a new mineral discovered in the famous for Pb-Cu-Ag-As-Tl with two Te/S atoms. One of five Ag sites and Hg site, which are bearing sulfosalts Lengenbach quarry in the Binn Valley, Valais, very close (separation 1.137 Å), are partially occupied (50%). Switzerland. Debattistiite has been identified in two specimens Thus there is a statistical distribution (50:50) between Hg(Te,S)2 from zone 1 of the quarry in cavities in dolomitic marble with and AgS2(Te,S)2 polyhedra in the structure. The conditions of realgar, rutile, trechmannite, and hutchinsonite. The mineral sulfotellurides formation in hydrothermal systems are discussed. occurs as very rare tabular euhedral black, opaque crystals up It is suggested that debattistiite formed from hydrothermal solu- to 150 μm with a metallic luster and a gray streak. It is brittle tions at temperatures >330 °C similar to those reported for the with uneven fracture and no cleavage. The Vickers hardness other Lengenbach sulfosalts. The mineral was named for Luca 2 De Battisti (b.1958), a systematic mineralogist and expert on the VHN25 = 80 (65–94) kg/mm , corresponding to a Mohs hardness of 2–2½. Density was not measured due to smal size of grains; minerals of Lengenbach quarry who collected the specimens of 3 debattistiite. Holotype material is deposited in the Museum of Dcalc = 5.647 g/cm . In reflected light debattistiite is dark gray, highly bireflectant and weakly pleochroic from dark gray to a Mineralogy, Department of Geosciences, University of Padova, slightly greenish gray. It is highly anisotropic with brownish Italy. D.B. to blue rotation tints. No internal reflections were observed. EVDOKIMOVITE* The reflectance values in air for the COM wavelengths [Rmin, O.L. Siidra, L.P. Vergasova, Y.L. Kretser, Y.S. Polekhovsky, S.K. Rmax, (nm)] are 27.2, 34.5 (471.1), 25.5, 31.0 (548.3), 22.9, 28.4 (586.6), 20.1, 25.2 (652.3). The average of 9 electron probe WDS Filatov, and S.V. Krivovichev (2014) Unique thallium miner- analyses [wt% (range)] is: Ag 44.88 (44.43–45.26), Hg 4.49 alization in the fumaroles of the Tolbachik volcano, Kamchat- (4.11–4.68), As 20.77 (20.21–21.30), S 17.72 (17.19–18.01), ka Peninsula, Russia. II. Evdokimovite, Tl4VO3(SO4)5(H2O)5. Te 11.82 (11.44–12.09), total 99.68. Other detectable elements Mineralogical Magazine, 78(7), 1711–1724. were at or below detection limits. The empirical formula based Evdokimovite (IMA 2013-041), ideally Tl4VO3(SO4)5(H2O)5 on 29.5 apfu is Ag9.01Hg0.49As6.01S11.98Te2.01. The strongest lines of the calculated X-ray powder diffraction pattern [d Å (I; hkl)] was discovered in a sample from a fumarole at the First scoria are: 10.56 (62; 001), 3.301 (47; 212), 2.991 (40; 212), 2.742 (95; cone, North Breach of the Great Fissure Tolbachik volcano erup- 2 11), 2.733 (100; 230). X-ray single-crystal diffraction study on tion, Kamchatka Peninsula, Russia. Evdokimovite occurs as thin a crystal fragment 70 × 50 × 40 μm shows the mineral is triclinic, colorless needles up to 0.09 mm long with no twinning in associa- space group P1; a = 7.832(5), b = 8.606(4), c = 10.755(5) Å, α tion with markhininite and karpovite. Other associated minerals = 95.563(9), β = 95.880(5), γ = 116.79(4)°, V = 635.3 Å3; Z = are pauflerite bobjonesite and shcherbinaite. The mineral has a white streak and adamantine luster. It is brittle with no cleavage or 1. In the crystal structure of debattistiite [refined to R1 = 0.0826 parting and has conchoidal fracture. The average microhardness 2 is VHN100 = 92 kg/mm ; Mohs hardness is ~ 2½. The density was 3 * All minerals marked with an asterisk have been approved by not measured; Dcalc = 4.20 g/cm for the ideal formula. In reflected the IMA CNMMC. light the mineral is light gray with beige tints, weak bireflectance † For a complete listing of all IMA-validated unnamed miner- and no pleochroism. Anisotropy is masked by abundant greenish- als and their codes, see http://pubsites.uws.edu.au/ima-cnmnc/. gray internal reflections. Reflectance values were measured in air 0003-004X/15/0007–1649$05.00/DOI: http://dx.doi.org/10.2138/am-2015-NMN10073 1649 1650 NEW MINERAL NAMES between 400 and 700 nm with 20 nm intervals. The values for black with a dark gray streak, is opaque, metallic, brittle with the COM wavelengths [Rmin, Rmax, (nm)] are 7, 7.2 (470); 6.7, 6.9 irregular fracture and shows no cleavage or parting. The esti- (546); 6.6, 6.8 (589); 6.4, 6.6 (650). The average of 30 electron mated Mohs hardness is 2½–3. Density could not be measured 3 probe EDS analysis [wt% (range)] is Tl2O 55.40 (54.2–56.01), due to the paucity of the material; Dcalc = 5.3 g/cm . Ferdowsiite VO2 14.92 (12.09–15.62), SO3 25.83 (24.39–27.03), H2O 5.75 is grayish-white in reflected light and shows no internal reflec- (calculated by stoichiometry and structural data), total 101.90. tions. Pleochroism is distinct, white to gray. Reflectance values The empirical formula calculated on the basis of (Tl + V + S) were measured between 400 and 700 nm in 20 nm intervals. The = 12 apfu is Tl4.10V2.83S5.07H10.00O27.94. A needle of evdokimovite values for (COM) wavelengths [Rmin, Rmax % (λ nm)] in air are: 0.05 × 0.01 × 0.008 mm was used for a single crystal study. 34.9, 37.3 (470); 33.4, 35.9 (546); 32.4, 35.1 (589); 30.7, 33.5 The crystal structure was solved by direct methods and refined (650). Anisotropism is distinct in air and enhanced in oil; rotation to R1 = 0.11 on the basis of 3660 independent [F ≥ 4σ(F)] re- tints vary between dark brown and bluish gray. The average of flections. It contains six symmetrically independent Tl+ sites, 10 electron probe WDS analyses on the holotype sample gave 4+ 6+ 4+ three V sites, and five S sites. The V O6 octahedra and SO4 [wt% (range)]: Ag 38.81 (37.99–39.33), Pb 0.76 (0.51–1.19), Sb tetrahedra share corners to form two types of vanadyl-sulfate 26.06 (25.23–27.84), As 10.64 (9.23–11.56), Bi 0.11 (0.00–0.22), 2– 2– chains, [(VO)(H2O)2(SO4)2] and [(VO)2(H2O)3(SO4)3] linked S 23.21 (22.68–23.75), total 99.59 wt%. The empirical formula by Tl atoms and H bonds. The structure can be described as based on 32 apfu is Ag7.97Pb0.08Sb4.75As3.15Bi0.01S16.04. The strongest a stacking of layers of A and B types. The A layer contains lines in the calculated X-ray powder-diffraction pattern [dcalc Å 2– [(VO)2(H2O)3(SO4)3] chains, Tl(2) and Tl(3) atoms. The B layer (Icalc%, hkl)] are: 3.225 (96, 113), 3.205 (100, 212); 2.8995 (78, 2– contains [(VO)(H2O)2(SO4)2] chains and Tl(1) atoms. The layers 020); 2.7559 (90, 301); 2.7073 (79, 105); 1.9401 (22, 206); stacked as ...A′*BAA′B*A*..., where A and A′ differ by opposite 1.9226 (22, 404). Single-crystal X-ray diffraction data refined 2– orientations of the [(VO)2(H2O)3(SO4)3] chains, and the A* and to R1 = 0.0282 for 626 unique reflections with I ≥ 4σ(I) shows B* layers are rotated by 180° relative to the A and B layers, re- the mineral is monoclinic, space group P21/n, a = 8.677(2), 2– 3 spectively. The chains [(VO)2(H2O)3(SO4)3] are modulated and b = 5.799(1), c = 13.839(3) Å, β = 96.175(4)°, V = 692.28 Å , are arranged to form elliptical tunnels hosting disordered Tl(4), and Z = 1. Ferdowsiite belongs to ABX2-type silver sulfosalts, Tl(4A), and Tl(4B) sites. Evdokimovite is monoclinic, P21/n, combining Sb and As, although its crystal structure is different a = 6.2958(14), b = 10.110(2), c = 39.426(11) Å, β = 90.347(6)°, from other members of this group. The structure of ferdowsiite V = 2509.4 Å3, Z = 4. The powder X-ray diffraction data were has four independent cation and four anion sites, where two are obtained from the crushed crystal used for the single crystal occupied by Ag, one by Sb, and the remaining site shows mixed analysis.

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