New Mineral Names (original) (raw)
In This Issue
This New Mineral Names has entries for 18 new minerals, including aradite, chlorkyuygenite, chubarovite, cryobostryxite, ferriakasakaite-(La), ferriandrosite-(La), ferro-pedrizite, flamite, flinteite, fluorchegemite, fluorkyuygenite, fluormayenite, fluor-tsilaisite, gatedalite, kononovite, mendigite, nabimusaite, and zadovite.
Aradite* and Zadovite*
E.V. Galuskin, F. Gfeller, I.O. Galuskina, A. Pakhomova, T. Armbruster, Y. Vapnik, R. Włodyka, P. Dzierżanowski, and M. Murashko (2015) New minerals with a modular structure derived from hatrurite from the pyrometamorphic Hatrurim Complex. Part II. Zadovite, BaCa6[(SiO4)(PO4)](PO4)2F and aradite, BaCa6[(SiO4)(VO4)](VO4)2F, from paralavas of the Hatrurim Basin, Negev Desert, Israel. Mineralogical Magazine, 79, 1073–1087.Galuskin EV, Gfeller F, Galuskina IO, Pakhomova A, Armbruster T, Vapnik Y, Włodyka R, Dzierżanowski P, Murashko M. , 2015"New minerals with a modular structure derived from hatrurite from the pyrometamorphic Hatrurim Complex. Part II. Zadovite, BaCa6[(SiO4)(PO4)](PO4)2F and aradite, BaCa6[(SiO4)(VO4)](VO4)2F, from paralavas of the Hatrurim Basin, Negev Desert, Israel" Mineralogical Magazine, vol. 79, p. 1073–1087.
Two new minerals aradite (IMA 2013-047), ideally BaCa6[(SiO4)(VO4)](VO4)2F and zadovite (IMA 2013-031), ideally BaCa6[(SiO4)(PO4)](PO4)2F, the members of the solid solution BaCa6[(SiO4),(PO4),(VO4)]4F, were discovered in a few centimeter thick paralava veins in gehlenite-rich pyrometamorphic rocks of the Hatrurim Complex, Gurim Anticline, Hatrurim Basin (31°12′N 35°14′E), located near the town of Arad in the Negev Desert, Israel. Aradite and zadovite are associated with rock-forming gehlenite, pseudowollastonite, wollastonite, andradite–schorlomite garnet-series, rankinite, magnesioferrite, kalsilite and fluorapatite; with minor P-rich ellestadite, larnite, cuspidine, and hematite. Accessory minerals are dorrite-khesinite, barioferrite, walstromite, barite, gurimite, fresnoite, delafossite, cuprite, vorlanite, perovskite, and hexacelsian. Zadovite and aradite are colorless, transparent with a white streak, have vitreous luster and uneven fracture. Both are uniaxial (–) with ω = 1.784(3), ∊ = 1.780(3) (aradite) and ω = 1.711(2), ∊ = 1.708(2) (zadovite) (589 nm). UV fluorescence was not observed. The micro-indentation hardness measured only for zadovite corresponds to a Mohs hardness of ~5–5½. Density was not measured directly due to small grain size; _D_calc = 3.509 (aradite) and 3.503 g/cm3 (zadovite). Raman spectra of both minerals show bands above 800 cm−1 from symmetric (ν1) and antisymmetric (ν3) stretching vibrations of (TO4), bands in the range 300–700 cm−1 attributed to bending vibrations (ν2 and ν4) of (TO4), and bands below 300 cm−1 assigned to stretching vibrations of Ca–O and also the vibration of R(TO4) and T(TO4). The Raman spectra reflect the varying PO4 (e.g. change of band intensity at ~1031 cm−1) and VO4 contents (e.g. change of band intensity at ~835 cm−1). The presence of SO4 leads to an additional Raman band at ~997 cm−1. Average of 5 (aradite) and 14 (zadovite) electron probe WDS analyses is [wt% (range)]: Na2O 2.36 (2.31–2.49), CaO 40.80 (40.53–40.99), SrO 0.32 (0.22–0.42), BaO 18.24 (18.09–18.79), Al2O3 0.03 (0–0.06), Fe2O3 0.10 (0.03–0.18), SiO2 7.89 (7.71–9.50), P2O5 5.46 (3.77–7.01), V2O5 22.09 (19.95–24.69), SO3 1.58 (0.84–2.22), F 2.36 (2.31–2.49), –O=F2 0.99, total 98.84 for aradite and Na2O 0.18 (0.16–0.21), CaO 42.26 (41.89–42.57), SrO 0.33 (0.24–0.38), BaO 19.92 (19.58–20.28), SiO2 8.43 (8.28–8.57), P2O5 19.29 (17.49–20.57), V2O5 7.51 (6.20–9.07), SO3 1.22 (0.98–1.37), F 2.45 (2.21–2.77), –O=F2 1.03, total 100.56 for zadovite. The empirical formula calculated on the basis of 17 (O+F) pfu is: BaCa6[(Si, P)O4)1.53(VO4)0.47][(VO4)1.51(PO4)0.49]F for aradite, and BaCa6[(SiO4)(PO4)][(PO4)1.39(VO4)0.61]F for zadovite. The strongest X-ray calculated powder diffraction lines [d Å (I%; hkl)] are: 8.734 (32; 003), 6.010 (33; 101), 3.565 (100; 110), 3.301 (48; 113), 3.201 (40; 107), 3.066 (32; 021), 2.762 (85; 116), 1.783 (32; 220) for aradite and 3.548 (87; 110), 3.279 (41; 113), 3.154 (88; 107), 3.051 (100; 021), 2.859 (63; 009), 2.738 (67; 116), 1.973 (55; 02.10), 1.774 (75; 220) for zadovite. X-ray single-crystal diffraction study [refined to _R_1 = 0.0304 for 399 unique _I_obs > 2σ(I) reflections for aradite and to _R_1 = 0.0124 for 702 unique _I_obs > 2σ(I) reflections for zadovite] on an aradite crystal fragment of 30×20×10 μm and on an zadovite crystal fragment of 150×60×60 μm shows that the minerals are trigonal, space group R_3_m, Z = 3, with cell parameters a = 7.1300(1), c = 26.2033(9) Å, V = 1153.63 Å3 for aradite, and a = 7.0966(1), c = 25.7284(3) Å, V = 1122.13 Å3 for zadovite. The structure of zadovite-series minerals belonging to the nabimusaite group is characterized by a 1:1 alternation of antiperovskite-like {[FCa6](TO4)2}4+ modules and Ba(TO4)24− modules. The name zadovite honors the Russian mineralogist Aleksandr Efimovich Zadov (1958–2012), author or co-author of more than 90 new mineral species. Aradite is named after the town of Arad near the type locality. Type material is deposited in the Museum of Natural History in Bern, Switzerland, catalog numbers NMBE 42103 (zadovite, the same type specimen is also the holotype for gurimite) and NMBE 42188 (aradite). F.C.
ChlorkyuyGenite*, FluorkyuyGenite*, Fluormayenite*
E.V. Galuskin, F. Gfeller, I.O. Galuskina, T. Armbruster, R. Bailau, and V.V. Sharygin (2015) Mayenite supergroup, part I: Recommended nomenclature. European Journal of Mineralogy, 27, 99–111.Galuskin EV, Gfeller F, Galuskina IO, Armbruster T, Bailau R, Sharygin VV. , 2015"Mayenite supergroup, part I: Recommended nomenclature" European Journal of Mineralogy, vol. 27, p. 99–111.
E.V. Galuskin, I.O. Galuskina, J. Kusz, F. Gfeller, T. Armbruster, R. Bailau, M. Dulski, V.M. Gazeev, N.N. Pertsev, A.E. Zadov, and P. Dzierżanowski (2015) Mayenite supergroup, part II: Chlorkyuygenite from Upper Chegem, Northern Caucasus, Kabardino-Balkaria, Russia, a new microporous mineral with “zeolitic” H2O. European Journal of Mineralogy, 27, 113–122.Galuskin EV, Galuskina IO, Kusz J, Gfeller F, Armbruster T, Bailau R, Dulski M, Gazeev VM, Pertsev NN, Zadov AE, Dzierżanowski P. , 2015"Mayenite supergroup, part II: Chlorkyuygenite from Upper Chegem, Northern Caucasus, Kabardino-Balkaria, Russia, a new microporous mineral with “zeolitic” H2O" European Journal of Mineralogy, vol. 27, p. 113–122.
E.V. Galuskin, F. Gfeller, T. Armbruster, I.O. Galuskina, Y. Vapnik, M. Dulski, M. Murashko, P. Dzierżanowski, V.V. Sharygin, S.V. Krivovichev, and R. Wirth (2015) Mayenite supergroup, part III: Fluormayenite, Ca12Al14O32[□4F2], and fluorkyuygenite, Ca12Al14O32[(H2O)4F2], two new minerals from pyrometamorphic rocks of the Hatrurim Complex, South Levant. European Journal of Mineralogy, 27, 123–136.Galuskin EV, Gfeller F, Armbruster T, Galuskina IO, Vapnik Y, Dulski M, Murashko M, Dzierżanowski P, Sharygin VV, Krivovichev SV, Wirth R. , 2015"Mayenite supergroup, part III: Fluormayenite, Ca12Al14O32[□4F2], and fluorkyuygenite, Ca12Al14O32[(H2O)4F2], two new minerals from pyrometamorphic rocks of the Hatrurim Complex, South Levant" European Journal of Mineralogy, vol. 27, p. 123–136.
Redefinition of the mayenite: The mayenite supergroup recommended nomenclature
The new mayenite supergroup nomenclature accepted by the IMA-CNMNC (proposal 2014/13-C) comprising two groups of minerals isostructural with mayenite (space group I_43_d, a ≈ 12 Å) with the general formula X12T14O32–x(OH)3x[W6–3x]: the mayenite group (oxides) and the wadalite group (silicates), for which the anionic charge over 6 W sites is –2 and –6, respectively (X = Ca; T = Al, Mg, Fe, Si, Ti; W = Cl, F, H2O, or vacant). A detailed re-examination of the type specimens of mayenite, originally described as Ca12Al14O33, shows its correct end-member formula as Ca12Al14O32[□4Cl2]. Consequently, mayenite was redefined as chlormayenite, while the name mayenite is reserved for a potential mineral with the end-member composition Ca12Al14O32[⎕5O]. As a consequence, the mineral brearleyite, Ca12Al14O32[⎕4Cl2], described in 2011 appeared to be identical with chlormayenite and is therefore discredited. By analogy with chlormayenite the kyuygenite recently approved by the IMA-CNMNC was renamed to chlorkyuygenite. Thus currently the mayenite group includes four species: chlormayenite Ca12Al14O32[⎕4Cl2] and three recently discovered minerals (see below) chlorkyuygenite, Ca12Al14O32[(H2O)4Cl2], fluormayenite Ca12Al14O32[⎕4F2], and fluorkyuygenite, Ca12Al14O32[(H2O)4F2]. The wadalite group includes two mineral species wadalite, Ca12Al10Si4O32[Cl6] and eltyubyuite Ca12Fe103+Si4O32[Cl6]. Minerals of the mayenite group have a zeolite-like structure with a {Al14O32}22– tetrahedral framework enclosing six big cages (~5 Å) each occupied by two Ca2+, which leads to an excess of two positive charges. At the centre of the cage (W site) anions balance the charge of the framework and Ca.
Chlorkyuygenite (IMA 2012-046), a new mineral with an ideal formula Ca12Al14O32[(H2O)4Cl2], was initially mentioned as “mayenite-Cl” then approved under the name kyuygenite and finally approved by IMA CNMNC (proposal 2014/13-C) as chlorkyuygenite according to mayenite group nomenclature. It was discovered as an accessory mineral in Ca-humite zones of calcareous skarn xenoliths in ignimbrites of the Upper Chegem Caldera, Northern Caucasus, Kabardino-Balkaria, Russia. The mineral thought to be crystallized initially as chlormayenite, which later was altered under influence of volcanic gases containing water vapor. Isometric grains and tris-tetrahedral crystals of chlorkyuygenite up to 50 μm and its aggregates up to 100–150 μm are enclosed in chegemite-fluorchegemite, reinhardbraunsite or srebrodolskite. Chlorkyuygenite also forms rims around wadalite crystals. Other associated minerals include kumtyubeite, rondorfite, hydroxylellestadite, lakargiite, perovskite, kerimasite, elbrusite, ettringite-group minerals, hydrocalumite, bultfonteinite, and the minerals of the katoite–grossular series. Larnite, spurrite and galuskinite are noted as relics in Ca-humites. Chlorkyuygenite is colorless, occasionally with a greenish or yellowish tint, and the white streak. The mineral has a strong vitreous luster. The micro-indentation hardness VHN50 = 632(37) kg/mm2 corresponds to 5–5½ of the Mohs scale; _D_calc = 2.941 g/cm3. Chlorkyuygenite is transparent, isotropic, n =1.672(1) (589 nm). The main bands in the Raman spectra (cm–1) are: 202 (O–Ca–O vibrations), 321, 511, 705, 776 and 881 (Al–O). A broad band with two maxima near 3400 and 3200 cm−1 is related to H–O stretching vibrations of H2O. Weak bands in the region of H2O-bending and OH-stretching vibrations are also noted. The temperature dependent Raman spectra show the molecular water is completely released from the mineral structure at about 550 °C. A FTIR spectrum shows main bands at 780 and 847 cm–1 (Al–O stretching vibrations). An average of 27 electron probe analysis of chlorkyuygenite [wt% (range)] is SiO2 0.70 (0.53–0.92), TiO2 0.17 (0.10–0.24), Al2O3 43.00 (42.1–44.1), Fe2O3 4.27 (3.86–4.81), Y2O3 <0.08, MgO <0.03, CaO 43.70 (43.1–44.2), Cl 5.13 (4.88–5.66), H2O 4.42 (calc. from O+Cl = 6, by stoichiometry), –O=Cl2 1.16, total 100.23, corresponding to the empirical formula Ca11.99(Al12.98Fe0.823+Si0.18Ti0.034+)Σ14.01O32[(H2O)3.77Cl2.23]Σ6. The most intensive calculated X-ray powder diffraction lines are [_d_calc Å (_I_calc%; _hkl_)]: 4.91 (31; 211), 3.215 (15; 321), 3.007 (38; 400), 2.690 (100; 420), 2.455 (46; 422), 2.196 (21; 521), 1.668 (26; 640). The crystal structure was solved by direct methods and refined to _R_1 = 0.0116 for 300 unique _I_ > 2σ(I) reflections in the space group I_43_d; a = 12.0285(1) Å, V = 1740.34 Å3, Z = 2. The structure differs from the one of chlormayenite by H2O molecules filling the empty structural cages of W sites. The tetrahedral framework of chlorkyuygenite {Al14O32}22– encloses six structural cages, each occupied by two Ca2+ ions, leading to an excess of positive charges which is balanced by incorporation of Cl– at two of six W sites. Chlorine is linearly coordinated by two Ca cations. The disordered character of Cl and H2O within the cages did not allow the determination of the proton positions. The original name of chlorkyuygenite (kyuygenite) is for the Kyuygen-Kaya Mountain in the northern part of the Upper Chegem caldera (type locality). Type material is deposited in the Naturhistorisches Museum of Bern, Switzerland and in the Fersman Mineralogical Museum Russian Academy of Sciences, Moscow, Russia (this specimen is the holotype for both chlorkyuygenite and chegemite).
Two new minerals, fluormayenite (IMA 2013-019), ideally Ca12Al14O32[⎕4F2], and fluorkyuygenite (IMA 2013-043) ideally Ca12Al14O32[(H2O)4F2], were discovered as major constituents of larnite pyrometamorphic rocks of the Hatrurim Complex (Mottled Zone) distributed along the Dead Sea rift on the territory of Israel, Palestinian Autonomy, and Jordan. The holotype specimens of fluormayenite and fluorkyuygenite were collected at the Jabel Harmun, Judean Mts., Palestinian Autonomy and in the Hatrurim Basin, Negev Desert, Israel, respectively. Mineral associations for both minerals are similar and include larnite, shulamitite, Cr-containing spinel–magnesioferrite series, ye’elimite, fluorapatite-fluorellestadite, periclase, brownmillerite, oldhamite as well as the retrograde phases portlandite, hematite, hillebrandite, afwillite, foshagite, ettringite, katoite, and hydrocalumite. Fluorkyuygenite thought to be crystallized initially as fluormayenite which later was altered by the water vapor-enriched gases during a combustion process. Fluormayenite and fluorkyuygenite form crystals, usually <20 μm in size, are colorless, occasionally with greenish or yellowish tint with a white streak and a vitreous luster. The micro-indentation hardness of fluormayenite and fluorkyuygenite is VHS50 = 771(38) and 712(83) kg/mm2 corresponding to ~5½–6 and 5–5½ of the Mohs scale respectively. Both minerals do not show fluorescence in UV light, are transparent, isotropic with _n_ = 1.612(3) and 1.610(3) (589 nm), respectively. Raman spectra of fluormayenite and fluorkyuygenite in the spectral region 200–1000 cm−1 are similar and are characterized by the bands at (cm−1): ~320, 520, 700, 770 (Al–O vibrations). Fluorkyuygenite shows a broad band between 2600–3500 cm−1 with a weak maxima at 3020 and 3200 (ν H2O) shifted towards a lower frequencies compare to chlorkyuygenite. Bands at 3560–3580 cm–1 related to OH groups substituting F. Fluormayenite shows OH bands at 3670–3680 cm–1. Temperature-dependent Raman spectra show the molecular water is completely released from the fluorkyuygenite structure at about 400 °C. The averages of electron probe WDS analyses of fluormayenite [wt% (range)] and fluorkyuygenite [{wt% (range)}], respectively are: SiO2 0.04 (0.02–0.08), {0.89 (0.44–1.41)}, Al2O3 48.85 (48.2–49.1), {45.00 (44.4–45.4)}, Fe2O3 1.51 (1.32–1.75), {2.10 (1.59–2.68)}, MgO 0.11 (0.08–0.15), {<0.02}, CaO 46.96 (47.4–47.8), {44.64 (44.0–45.2)}, Na2O 0.08 (0.06–0.10), {<0.02}, SO3 0.08 (0.04–0.12), {<0.03}, P2O5 0.03 (0.03–0.06), {<0.03}, Cl 0.11 (0.09–0.12), {<0.02}, F 1.83 (1.58–2.11), {2.38 (1.84–2.84)}, H2O 1.09, {4.72} [calculated as 6 – (F + Cl + OH)], –O=(F+Cl)2 0.80, {1.00}, total 99.88, {98.72}. The corresponding empirical formulae are (Ca11.95Na0.04)Σ11.99(Al13.68Fe0.273+Mg0.04Si0.01P0.01S0.016+)Σ14.02O31.50(OH)1.49[⎕4.58F1.38Cl0.04]Σ6, and Ca12.03(Al13.34Fe0.403+Si0.22)Σ13.97O32[(H2O)3.81F1.89(OH)0.30]Σ6, respectively. The most intense calculated X-ray powder diffraction lines for fluormayenite are [_d_calc Å (_I_calc%; _hkl_)]: 4.885 (41; 211), 3.198 (46; 321), 2.992 (61; 400), 2.676 (100; 420), 2.443 (45; 422), 2.185 (32; 521) and those for fluorkyuygenite are: 4.895 (92; 211), 3.204 (26; 321), 2.997 (47; 400), 2.681 (100; 420), 2.447 (43; 422), 2.189 (41; 521). The crystal structures of both minerals were solved by direct methods in the space group _I_43_d, Z_ = 2 and refined to _R_1 = 0.0302 using 686 unique _I_ > 2σ(I) reflections for fluormayenite [a = 11.9894(2) Å, V = 1723.42 Å3] and to _R_1 = 0.0274 using 280 unique I > 2σ(I) reflections for fluorkyuygenite [a = 11.966(2) Å, V = 1713.4 Å3]. In fluormayenite ⅓ of the structural cages of the tetrahedral framework are occupied by fluorine. In fluorkyuygenite, in addition to fluorine and negligible amounts of OH, H2O molecules occupy about ⅔ of the cages. The new minerals were named as fluorine analogs of chlormayenite and chlorkyuygenite. The holotype of fluormayenite is deposited in the Museum of Natural History in Bern, Switzerland. Fragments of the fluorkyuygenite holotype, which at the same time are fragments of the shulamitite holotype, were deposited in the Mineralogical Museum of St. Petersburg University, Russia, in the Central Siberian Geological Museum of the V.S. Sobolev Institute of Geology and Mineralogy, Novosibirsk, Russia and in the Fersman Mineralogical Museum of Russian Academy of Sciences, Moscow, Russia. D.B.
Chubarovite*
I.V. Pekov, N.V. Zubkova, L.A. Pautov, V.O. Yapaskurt, N.V. Chukanov, I.S. Lykova, S.N. Britvin, E.G. Sidorov, and D.Yu. Pushcharovsky (2015) Chubarovite, KZn2(BO3)Cl2, a new mineral species from the Tolbachik volcano, Kamchatka, Russia. Canadian Mineralogist, 53, 273–284.Pekov IV, Zubkova NV, Pautov LA, Yapaskurt VO, Chukanov NV, Lykova IS, Britvin SN, Sidorov EG, Pushcharovsky DYu. , 2015"Chubarovite, KZn2(BO3)Cl2, a new mineral species from the Tolbachik volcano, Kamchatka, Russia" Canadian Mineralogist, vol. 53, p. 273–284.
Chubarovite (IMA 2014-018), ideally KZn2(BO3)Cl2, was discovered in the sublimates of active fumaroles at the First and Second scoria cones of the Northern Breakthrough of the Great Tolbachik Fissure Eruption, Tolbachik volcano, Kamchatka, Russia. In the Arsenatnaya fumarole at the Second scoria cone (holotype) chubarovite occurs in association with fluoborite, krasheninnikovite, sylvite, halite, langbeinite, aphthitalite, arcanite, zincite, flinteite, wulffite, johillerite, urusovite, pseudobrookite, vanthoffite, svabite, orthoclase, fluorphlogopite, hematite, and tenorite; while at the First scoria cone, it is found with sellaite, fluorite, anhydrite, halite, cotunnite, challacolloite, sofiite, and flinteite. Sometimes chubarovite overgrows challacolloite crystals. Chubarovite forms hexagonal or trigonal lamellar to tabular crystals up to 1.5×0.5 mm (typically 0.2×0.8 mm) with pinacoidal and rhombohedral faces. Crystals are well-shaped or crude, sometimes divergent, resembling flowers or an open book. Simple twins of two types are observed: contact twins with the axis [001] and single composition surface {001} and, more rare, X-shaped penetration twins on (103). Commonly crystals are combined in open-work groups, drusy aggregates or compact clusters or crusts up to 1 cm across. Areas covered with chubarovite are up to 20 cm2. Chubarovite is transparent, colorless, has a white streak and vitreous luster. It is flexible but not elastic, lamellae can be easily bent. The cleavage is perfect on {001} and the fracture is laminated. Mohs hardness is ~2; _D_meas = 2.68 and _D_calc = 2.716 g/cm3. The mineral is non-fluorescent. Optically chubarovite is uniaxial (–), with ω = 1.541(2), ∊ = 1.539(2) (589 nm); colorless, non-pleochroic. The main bands at IR spectrum (cm–1, s = strong band, w = weak band, sh = shoulder) are: 1344w sh, 1257s (degenerate stretching mode of the orthoborate group), 747, 695 (combinations of degenerate and nondegenerate modes of BO3 groups), 496w, 402s (lattice modes involving Zn–O stretching vibrations and both translational and librational vibrations of BO3 groups). No bands corresponding to H2O, OH, or covalent C–O bonds were observed. The averaged 4 point WDS electron probe analyses gave [wt%, (range)]: K2O 16.48 (16.27–16.69), Rb2O 0.46 (0.44–0.48), ZnO 53.96 (53.63–54.16), B2O3 10.98, Cl 24.48 (24.16–24.79), –O=Cl2 5.53, total 100.03. The empirical formula is (K1.05Rb0.01)Σ1.06Zn2.00B0.95O2.92Cl2 based on (O+Cl) = 5 apfu. The strongest lines of the X-ray powder diffraction pattern are [d Å (I%; hkl)]: 8.79 (100; 003), 4.394 (43; 006), 4.225 (25; 101), 4.074 (91; 012), 3.590 (90; 104), 3.324 (30; 015), 2.470 (67; 110), 2.245 (25; 1.0.10). The crystal structure of chubarovite was solved by direct methods and refined to R = 2.01%. The new mineral is trigonal, _R_32, a = 4.9429(4), c = 26.348(2) Å, V = 557.50 Å3, and Z = 3. The crystal structure is of a novel type and is based on anionic and cationic layers alternating along [001]. The anionic layer {Zn2(BO3)Cl2}–, consists of [BO3] groups sharing all O vertices with bases of [ZnO3Cl] tetrahedra, with each triangle connected to six Zn tetrahedra. Each Cl vertex is shared between one Zn tetrahedron and three edge-connected KCl6 octahedra that belong to the cationic layer of K+ cations. The mineral is named in honor of the Russian mineralogist and physicist Valeriy Mikhailovich Chubarov (b. 1948). The type specimen is deposited in the Fersman Mineralogical Museum of the Russian Academy of Sciences, Moscow, Russia. Yu.U.
Cryobostryxite*
I.V. Pekov, N.V. Zubkova, S.N. Britvin, V.O. Yapaskurt, N.V. Chukanov, I.S. Lykova, E.G. Sidorov, and D.Yu. Pushcharovsky (2015) New zinc and potassium chlorides from fumaroles of the Tolbachik volcano, Kamchatka, Russia: Mineral data and crystal chemistry. III. Cryobostryxite, KZnCl3·2H2O. European Journal of Mineralogy, 27, 805–812.Pekov IV, Zubkova NV, Britvin SN, Yapaskurt VO, Chukanov NV, Lykova IS, Sidorov EG, Pushcharovsky DYu. , 2015"New zinc and potassium chlorides from fumaroles of the Tolbachik volcano, Kamchatka, Russia: Mineral data and crystal chemistry. III. Cryobostryxite, KZnCl3·2H2O" European Journal of Mineralogy, vol. 27, p. 805–812.
Cryobostryxite (IMA 2014-058), ideally KZnCl3·2H2O, is a new mineral formed in the upper, moderately hot (30–80 °C) zone of an active fumaroles at the First scoria cone of the Northern Breakthrough of the Great Tolbachik Fissure Eruption, Tolbachik volcano, Kamchatka, Russia. It is probably formed as a product of the interactions between high-temperature volcanic sublimates and meteoric water. Cryobostryxite occurs on a surface of basalt scoria or in incrustations consisting of sellaite, fluorite, halite and/or anhydrite. Other associated minerals are gypsum, ralstonite and opal. Earlier, primary minerals of the assemblage are sellaite, fluorite, halite, anhydrite, cotunnite, sofiite, flinteite, chubarovite, anglesite, challacolloite, zincomenite, saltonseaite, hollandite, hematite, jakobssonite, leonardsenite, and olsacherite. Cryobostryxite forms anthodites up to 2 mm long and 0.5 mm thick, their near-parallel columnar or chaotic open-work aggregates up to 4–5 mm, sugar-like crusts up to 2×2 mm and up to 0.3 mm thick, rarely, coarse prismatic to acicular crystals up to 0.2–1 mm. The mineral is transparent, colorless, with a white streak and a vitreous luster. Cleavage was not observed. It is brittle with Mohs hardness ~2; _D_meas = 2.30(2), _D_calc = 2.300 g/cm3. Cryobostryxite is optically biaxial (+) with α = 1.522(2), β = 1.530(2), γ = 1.576(2) (589 nm); 2_V_estimated = 30(15). The strongest bands in the IR spectrum (cm–1) are: 3600–3200 (O–H stretching), 1607 (H–O–H bending), 508 (vibrations of H2O molecule as a whole). Weak bands in the range 600–1200 correspond to overtones and combination modes. Absorptions corresponding to B–O, C–O, N–O, and N–H bonds are absent. The average of 4 spot electron probe WDS analyses [wt% (range)] is: K 14.85 (14.12–15.58), Tl 4.08 (3.61–4.68), Zn 25.82 (24.83–27.11), Cl 41.70 (41.18–42.24), H2O (calc. as 2 molecules pfu) 14.19, total 100.64. The empirical formula calculated on the basis of K+Tl+Zn+Cl = 5 apfu is (K0.96Tl0.05)Σ1.01Zn1.00Cl2.99·2H2O. Cryobostryxite belongs to a new chemical family of minerals, which includes flinteite K2ZnCl4 and mellizinkalite K3Zn2Cl7. The strongest lines of the X-ray powder diffraction pattern are [d Å (I%; hkl)]: 7.62 (30; 011), 5.986 (43; 100), 5.766 (35; 002), 3.907 (33; 121), 3.466 (20; 121), 3.062 (100; 202,023), 2.996 (24; 211,200), 2.853 (27; 114). The crystal structure refined to _R_1 = 0.0654 for 1259 I > 2σ(I) independent reflections. Cryobostryxite is monoclinic, space group _P_21/c, a = 6.2795(3), b = 10.1397(3), c = 12.0829(7) Å, β = 107.732(5)°, V = 732.79 Å3, and Z = 4. The crystal structure contains isolated Zn-centered tetrahedra ZnCl3(H2O), which are connected via eight-coordinated K-centered polyhedra KCl7(H2O) to form a pseudo-framework. Both Zn- and K-centered polyhedra involve only O(1) atoms of the H2O(1) molecules, whereas H2O(2) molecules are located in holes of the K-Zn-Cl-H2O(1) polyhedral pseudo-framework and form hydrogen bonds. The mineral name is based on two Greek words, κρύος, cold or ice, and βόστρνξ, curl, reflecting very similar appearance of the anthodites of the mineral to ice curls. Cotype specimen is deposited in the Fersman Mineralogical Museum of the Russian Academy of Sciences, Moscow, Russia. D.B.
Ferriakasakaite-(La)* and Ferriandrosite-(La)*
M. Nagashima, D. Nishio-Hamane, N. Tomita, T. Minakawa, and S. Inaba (2015) Ferriakasakaite-(La) and ferriandrosite-(La): New epidote supergroup minerals from Ise, Mie Prefecture, Japan. Mineralogical Magazine, 79, 735–753.Nagashima M, Nishio-Hamane D, Tomita N, Minakawa T, Inaba S. , 2015"Ferriakasakaite-(La) and ferriandrosite-(La): New epidote supergroup minerals from Ise, Mie Prefecture, Japan" Mineralogical Magazine, vol. 79, p. 735–753.
Ferriakasakaite-(La) (IMA 2013-126), ideally A1CaA2LaM1Fe3+M2AlM3Mn2+(SiO4)(Si2O7)O(OH) and ferriandrosite-(La) (IMA 2013-127), ideally A1Mn2+A2LaM1Fe3+M2AlM3Mn2+(SiO4)(Si2O7)O(OH), are two new minerals discovered in the Shobu area, Ise City, Mie Prefecture, Japan. The minerals were found in tephroite-calcite veinlets cutting the stratiform ferromanganese deposit, in association with rhodochrosite, bementite and allanite-group minerals. Ferriakasakaite-(La) and ferriandrosite-(La) are indistinguishable macroscopically or by optical microscopy. The new minerals mostly occur as euhedral to subhedral prismatic crystals elongated by [010], with lengths varying from several micrometers to 150 μm. Crystals are dark brown with a vitreous luster and are brittle with imperfect cleavage on {001}. The data on optical properties and density are not given; _D_calc = 4.22 [ferriakasakaite-(La)] and 4.23 g/cm3 [ferriandrosite-(La)]. The average of 3 WDS electron probe analyses of ferriakasakaite-(La) is [wt% (range)]: SiO2 29.15 (29.11–29.30), TiO2 0.75 (0.71–0.80), Al2O3 9.35 (9.28–9.43), Cr2O3 0.06 (0.05–0.08), V2O3 4.11 (3.96–4.19), Fe2O3 5.96 (5.18–6.77), FeO 5.05 (4.45–5.94), MnO 10.90 (9.98–11.55), NiO 0.03 (0.01–0.05), MgO 0.46 (0.44–0.48), CaO 5.38 (5.07–5.57), SrO 0.01 (0–0.02), BaO 0.02 (0–0.03), K2O 0.03 (0–0.05), P2O5 0.03 (0–0.05), Y2O3 0.03 (0–0.07), La2O3 12.73 (12.01–13.06), Ce2O3 5.25 (5.22–5.31), Pr2O3 1.93 (1.80–2.09), Nd2O3 4.97 (4.62–5.29), Gd2O3 0.51 (0.48–0.56), Er2O3 0.09 (0.04–0.16), F 0.05 (0.02–0.08), –O=F2 0.02, H2O (by difference) 3.17, total 100.00; and the average of 3 WDS electron probe analyses of ferriandrosite-(La) is: SiO2 29.25 (29.05–29.54), TiO2 0.86 (0.62–1.07), Al2O3 9.61 (9.58–9.66), Cr2O3 0.08 (0.02–0.12), V2O3 3.40 (3.31–3.53), Fe2O3 5.48 (5.23–5.61), FeO 5.23 (4.88–5.45), MnO 12.05 (11.41–12.85), NiO 0.02 (0–0.05), MgO 0.65 (0.58–0.71), CaO 4.26 (3.77–4.86), SrO 0.04 (0–0.10), Y2O3 0.01 (0–0.02), La2O3 12.97 (12.34–13.57), Ce2O3 5.25 (5.14–5.36), Pr2O3 2.05 (1.92–2.11), Nd2O3 5.16 (4.72–5.38), Gd2O3 0.48 (0.28–0.65), Er2O3 0.01 (0–0.04), F 0.28 (0.27–0.30), –O=F2 0.12, H2O (by difference) 3.01, total 100.00. The empirical formulae are respectively: A1(Ca0.54Mn0.462+)A2[(La0.48Ce0.20Pr0.07Nd0.18Gd0.02)∑0.95Ca0.05]M1(Fe0.423+V0.343+Al0.18Ti0.064+)M2(Al0.96Fe0.043+)M3(Mn0.502+Fe0.432+Mg0.07)(SiO4)(Si2O7)O(OH) and A1(Mn0.562+Ca0.44)A2[(La0.49Ce0.20Pr0.08Nd0.19Gd0.02)∑0.97Ca0.03]M1(Fe0.403+V0.283+Al0.20Fe0.052+Ti0.074+)M2(Al0.97Fe0.033+)M3(Mn0.502+Fe0.402+Mg0.10)(SiO4)(Si2O)O(OH) based on 8 cations pfu (combined with the structure refinement). FeO and Fe2O3 were calculated based on charge balance where the total positive charge = 25. The strongest lines in the calculated X-ray powder-diffraction pattern of ferriakasakaite-(La) [_d_calc (Å) (_I_calc%; hkl)] are: 2.899 (100; 113), 2.614 (311), 3.509 (47; 211), 2.871 (40; 020), 2.710 (35; 013), 2.706 (35; 120) and those for ferriandrosite-(La) [_d_calc Å (_I_calc%; hkl)] are: 2.900 (100; 113), 2.615 (53; 311), 3.510 (46; 211), 2.870 (40; 020), 2.710 (35; 013), 2.706 (35; 120). Single-crystal X-ray diffraction data collected on a crystal of size 0.06×0.04×0.02 mm refined to _R_1 = 0.0313 for 1500 unique reflections shows ferriakasakaite-(La) is monoclinic, space group _P_21/m, with a = 8.8733(2), b = 5.7415(1), c = 10.0805(3) Å, β = 113.845(2)°, V = 469.73 Å3, and Z = 2. For ferriandrosite-(La), single-crystal X-ray diffraction data collected on a crystal of size 0.04×0.04×0.04 mm refined to _R_1 = 0.0293 for 2733 unique reflections shows the mineral is monoclinic, space group _P_21/m, with a = 8.8779(1), b = 5.73995(1), c = 10.0875(2) Å, β = 113.899(1)°, V = 469.97 Å3, and Z = 2. The new minerals have the epidote structure, with new combinations of dominant cations at A1 and M3 sites, which are the key sites to determine a root name for epidote-supergroup minerals: Ca and Mn2+ for ferriakasakaite-(La), respectively, and Mn2+ and Mn3+ for ferriandrosite-(La), which is the M3Fe3+ equivalent of androsite. Ferriakasakaite-(La) is named in honor of Masahide Akasaka (b. 1950) for his outstanding contribution to mineralogy. Ferriandrosite-(La) is based on the “ferriandrosite-(REE)” new root of the allanite group proposed by Armbruster et al. (2006). Type specimens of ferriakasakaite-(La) and ferriandrosite-(La) are deposited in the National Museum of Nature and Science, Tokyo, Japan. O.C.G.
Reference cited
Armbruster, T., Bonazzi, P., Akasaka, M., Bermanec, V., Chopin, C., Heuss-Assbischler, S., Liebscher, A., Menchetti, S., Pan, Y., and Pasero, M. (2006) Recommended nomenclature of epidote-group minerals. European Journal of Mineralogy, 18, 551–567.Armbruster T, Bonazzi P, Akasaka M, Bermanec V, Chopin C, Heuss-Assbischler S, Liebscher A, Menchetti S, Pan Y, Pasero M. , 2006"Recommended nomenclature of epidote-group minerals" European Journal of Mineralogy, vol. 18, p. 551–567.
Ferro-Pedrizite*
S.I. Konovalenko, S.A. Ananyev, N.V. Chukanov, S.M. Aksenov, R.K. Rastsvetaeva, A.I. Bakhtin, A.G. Nikolaev, R.R. Gainov, F.G. Vagizov, A.N. Sapozhnikov, D.I. Belakovskiy, Y.V. Bychkova, G. Klingelhöfer, and M. Blumers (2015) Ferro-pedrizite, NaLi2(Fe2+2Al2Li)Si8O22(OH)2, a new amphibole-supergroup mineral from the Sutlug pegmatite, Tyva Republic, Russia. European Journal of Mineralogy, 27, 417–426.Konovalenko SI, Ananyev SA, Chukanov NV, Aksenov SM, Rastsvetaeva RK, Bakhtin AI, Nikolaev AG, Gainov RR, Vagizov FG, Sapozhnikov AN, Belakovskiy DI, Bychkova YV, Klingelhöfer G, Blumers M. , 2015"Ferro-pedrizite, NaLi2(Fe2+2Al2Li)Si8O22(OH)2, a new amphibole-supergroup mineral from the Sutlug pegmatite, Tyva Republic, Russia" European Journal of Mineralogy, vol. 27, p. 417–426.
Ferro-pedrizite (IMA2014-037), ideally NaLi2(Fe2+2Al2Li)Si8O22(OH)2, is a new amphibole-supergroup mineral discovered in the Sutlug pegmatite in the Targi River Basin, Tyva Republic, Eastern Siberia, Russia. The associated minerals are quartz, albite, microcline, spodumene, cassiterite, beryl, columbite-(Mn), fergusonite-β-(Y), fluorapatite, schorl, trilithionite and fluorite. Ferro-pedrizite forms dark gray-blue to violet-blue acicular and long prismatic crystals up to 2×5×50 mm, with major crystal forms {110} prism and the {100} and {010} pinacoids, in random, radial or subparallel aggregates. Ferro-pedrizite is intensely colored, dark gray-blue to violet-blue, with pale gray streak, and vitreous luster. Ferro-pedrizite is brittle, has a Mohs hardness of 6 and a splintery fracture. It has a perfect cleavage on {110} and a less perfect one on {001}. _D_meas = 3.13(1) g/cm3 (by flotation in heavy liquids) and 3.16(1) g/cm3 (by hydrostatic weighting), and _D_calc = 3.138 g/cm3. No fluorescence under UV light was observed. Ferro-pedrizite is biaxial (–), α = 1.614(3), β = 1.638(3), γ = 1.653(3) (589 nm); 2_V_meas = 75(5)°, 2_V_calc = 76°. The orientation is: Y = b, Z ^ c = 3–4°, X ^ a ≈ 16°. Positive elongation is observed for the crystals parallel to the planes {010} and (YZ). The dispersion of the optical axes is weak, r < _v_. The mineral is weakly pleochroic _X_ (colorless) < _Y_ ≈ _Z_ (pale lilac-gray). IR spectrum of ferro-pedrizite show bands in the ranges 550–600 (Li–O-stretching vibrations), from 650 to 800 cm−1 (O–Si–O and M···O–H bending vibration), from 900 to 1150 cm−1 (Si–O stretching vibrations), and 3600–3750 cm−1 (O–H-stretching vibrations). Bands below 600 cm−1 correspond to M–O stretching and Si–O–Si bending modes. Average of 5 electron probe EDS analyses is [wt% (range)]: Li2O 4.67 (by the ICP-MS), Na2O 2.54 (2.43–2.67), K2O 0.13 (0–0.23), CaO 0.29 (0.20–0.35), MgO 4.48 (4.27–4.64), MnO 0.59 (0.43–0.65), FeOtotal 13.20 (13.02–13.37), FeO 9.06 and Fe2O3 4.60 (by Mössbauer spectroscopy), Al2O3 13.13 (12.80–13.46), SiO2 57.59 (57.25–57.91), F 1.15(1) (by wet chemical analyses), H2O 1.50(1) (by gas chromatography), –O=F2 0.48, total 99.25. The empirical formula calculated on the basis of 24 (O+F) pfu is: (Na0.60K0.02)Σ0.62(Li1.89Na0.07Ca0.04)Σ2.00(Fe1.032+Mg0.90Mn0.072+Al1.88Fe0.473+ Li0.65)Σ5.00[(Si7.79Al0.21)Σ8.00O22][(OH)1.36F0.49O0.15)]. The strongest X-ray powder diffraction lines [_d_ Å (_I_%; _hkl_)] are: 8.147 (52; 110), 4.420 (22; 040), 3.009 (100; 310), 2.7102 (28; 330), 2.6865 (29; 151), 2.6236 (21; 461). The monoclinic unit-cell parameters refined from the powder data are: _a_ = 9.376(4), _b_ = 17.663(2), _c_ = 5.277(6) Å, β = 102.22(1)°, _V_ = 854.1 Å3. X-ray single-crystal diffraction study [refined to _R_1 = 0.0391 for 4843 unique _I_ > 2σ(I) reflections on a twinned crystal fragment of 150×180×200 μm shows that the mineral is monoclinic, space group _C_2/m, a = 79.3716(4), b = 17.694(1), c = 5.2800(6) Å, β = 102.22(1)°, V = 853.5 Å3, Z = 2. The name follows the classification for amphiboles approved by IMA-CNMNC (Hawthorne et al. 2012). The type specimen is deposited in the Mineralogical Museum of the Tomsk State University, Russia, with the registration number 19116. F.C.
Reference cited
Hawthorne, F.C., Oberti, R., Harlow, G.E., Maresch, W.V., Martin, R.F., Schumacher, J.C., and Welch, M.D. (2012) IMA report: Nomenclature of the amphibole supergroup. American Mineralogist, 97, 2031–2048.Hawthorne FC, Oberti R, Harlow GE, Maresch WV, Martin RF, Schumacher JC, Welch MD. , 2012"IMA report: Nomenclature of the amphibole supergroup" American Mineralogist, vol. 97, p. 2031–2048.
Flamite*
E.V. Sokol, Y.V. Seryotkin, S.N. Kokh, Y. Vapnik, E.N. Nigmatulina, S.V. Goryainov, E.V. Belogub, and V.V. Sharygin (2015) Flamite, (Ca, Na, K)2(Si, P)O4, a new mineral from ultrahigh-temperature combustion metamorphic rocks, Hatrurim Basin, Negev Desert, Israel. Mineralogical Magazine, 79, 583–596.Sokol EV, Seryotkin YV, Kokh SN, Vapnik Y, Nigmatulina EN, Goryainov SV, Belogub EV, Sharygin VV. , 2015"Flamite, (Ca, Na, K)2(Si, P)O4, a new mineral from ultrahigh-temperature combustion metamorphic rocks, Hatrurim Basin, Negev Desert, Israel" Mineralogical Magazine, vol. 79, p. 583–596.
F. Gfeller, R. Widmer, B. Krüger, E.V. Galuskin, I.O. Galuskina, and T. Armbruster. (2015) The crystal structure of flamite and its relation to Ca2SiO4 polymorphs and nagelschmidtite. European Journal of Mineralogy, 27, 755–769.Gfeller F, Widmer R, Krüger B, Galuskin EV, Galuskina IO, Armbruster T. , 2015"The crystal structure of flamite and its relation to Ca2SiO4 polymorphs and nagelschmidtite" European Journal of Mineralogy, vol. 27, p. 755–769.
The new mineral species flamite (IMA 2013-122), with general formula (Ca, Na, K)2(Si, P)O4, a natural analog of the P, Na, K-doped high-temperature α-Ca2SiO4 modification, was discovered as a rock-forming mineral in Ca- and Al-rich paralava, an ultrahigh-temperature combustion metamorphic rock found in the Hatrurim Basin in Negev Desert, Israel. Thin paralava veinlets in gehlenite hornfels, had experienced slight retrograde alteration. The mineral assemblage consists of ~40% Ca2SiO4 solid solutions (flamite as a regular lamellar intergrowth with partially hydrated larnite), ~30% gehlenite, 15% rankinite, and 10% Ti-rich andradite. Minor phases (~5 vol%) are Fe-rich perovskite, magnesioferrite, and hematite, which contains tubular inclusions of cloudy flamite. Ettringite and calcium silicate hydrates are minor retrograde phases. Flamite occurs as 100–250 µm anhedral lamellar crystals filling interstitial areas between gehlenite and as intergrowths with rankinite and Ti-rich andradite. The mineral is pale yellow or gray, transparent with a white streak, vitreous luster and no parting or cleavage. The micro-indentation hardness VHN50 = 706 (579–753) kg/mm2 corresponding to 5–5½ of Mohs scale. The density was not measured due to intimate intergrowths with larnite; _D_calc = 3.264 g/cm3. No fluorescence in UV light was observed. Flamite is optically uniaxial (+), with ω = 1.634(2) and ∊ = 1.640(2) (589 nm); Z = ∊. The main bands in the Raman spectrum (cm–1) are: 170, 260, 520, 538, 850, 863, 885, 952, and 1003. Generally, the bands are associated with vibrations of isolated [SiO4] groups and Ca2+ cations (translational modes). No bands related to the presence [CO3]2–, OH groups or H2O were detected. The average of 21 electron probe analyses of the holotype sample [wt% (range)] is: CaO 59.76 (58.27–61.23), SiO2 28.87 (28.14–30.17), Al2O3 0.04 (0–0.08), FeO 0.15 (0–0.48), MgO 0.16 (0.08–0.55), BaO 0.05 (0–0.17), SrO 0.24 (0.17–0.35), V2O5 0.10 (0–0.16), P2O5 6.01–8.55, Na2O 1.55 (1.12–1.98), K2O 1.73 (1.40–2.04), total 100.03. The empirical formula is [Ca1.82Na0.09K0.06(Mg, Fe, Sr, Ba)0.02]Σ1.99(Si0.82P0.18)Σ1.00O4. Flamite dissolves in 10% HCl with the formation of a SiO2 gel. The strongest lines in the calculated powder X-ray diffraction pattern are [_d_calc Å (_I_calc%; hkl)]: 2.765 (44; 082), 2.759 (42; 4.14.1), 2.713 (100; 8.16.0), 2.518 (29; 8.16.1), 1.762 (32). According the original single crystal XRD study flamite is hexagonal, space group _P_63; a = 43.3726(18), c = 6.8270(4) Å; V = 11 122.2 Å, Z = 128. The later re-examination of the holotype material revealed that flamite is orthorhombic, crystallizes in the space group _Pnm_21, with a = 9.3845(6), b = 21.7310(14), c = 6.8346(4) Å, V = 1393.81 Å3, Z = 4, and better described by the formula Ca8−x(Na, K)x(SiO4)4−x(PO4)x. It is isostructural with the known synthetic P-doped clinker phase Ca15⎕(SiO4)6(PO4)2. The flamite structure is a derivative of the hexagonal high-temperature variety of dicalcium-silicate, so-called α-C2S, and is characterized by a cyclic triplet of individuals rotated 120° around c, interpreted as symplectite-like transformation “twinning” derived from α-C2S. The composition of intergrown flamite lamellae is chemically variable concerning the degree of Na, K, and P substitution. In terms of the structure flamite is closely related to nagelschmidtite, Ca7(SiO4)2(PO4)2, and the high-temperature polymorphs of C2S. The mineral name is derived from “flame” and refers to the origin of the mineral by ultrahigh-temperature combustion metamorphism triggered by fossil-fuel ignition. The holotype specimen is stored in the collections of the Central Siberian Geological Museum of the V.S. Sobolev, Institute of Geology and Mineralogy, Novosibirsk, Russia. D.B.
Flinteite*
I.V. Pekov, N.V. Zubkova, V.O. Yapaskurt, S.N. Britvin, M.F. Vigasina, E.G. Sidorov, and D.Yu. Pushcharovsky (2015) New zinc and potassium chlorides from fumaroles of the Tolbachik volcano, Kamchatka, Russia: Mineral data and crystal chemistry. II. Flinteite, K2ZnCl4. European Journal of Mineralogy, 27, 581–588.Pekov IV, Zubkova NV, Yapaskurt VO, Britvin SN, Vigasina MF, Sidorov EG, Pushcharovsky DYu. , 2015"New zinc and potassium chlorides from fumaroles of the Tolbachik volcano, Kamchatka, Russia: Mineral data and crystal chemistry. II. Flinteite, K2ZnCl4" European Journal of Mineralogy, vol. 27, p. 581–588.
The new mineral flinteite (IMA 2014-009), ideally K2ZnCl4, was discovered in active fumaroles at two neighbored scoria cones of the Northern Breakthrough of the Great Tolbachik Fissure Eruption, Tolbachik volcano, Kamchatka, Russia. At the First scoria cone (locality of the holotype) flinteite is a common mineral associated with halite, sellaite, fluorite, saltonseaite, chubarovite, and hollandite. At the Second scoria cone flinteite found in the Arsenatnaya fumarole in areas with the temperature 300–360 °C (with langbeinite, calciolangbeinite, aphthitalite, fluoborite, sylvite, halite, arcanite, tenorite, zincite, chubarovite, krasheninnikovite, vanthoffite, wulffite, johillerite, and urusovite on the earlier sublimated orthoclase, fluorphlogopite, hematite, and pseudobrookite) and in the sulphate-chloride zone of the Glavnaya Tenoritovaya fumarole at temperature 110 °C (with belloite, avdoninite, eriochalcite, mellizinkalite, sylvite, halite, carnallite, mitscherlichite, sanguite, chrysothallite, romanorlovite, gypsum, chlorothionite, and kainite). Flinteite typically forms prismatic crystals up to 0.2×0.3×1.2 mm, their groups, granular aggregates or crusts up to 0.5×5×5 mm. The mineral is transparent, light green, light yellow to bright greenish-yellow or colorless with a vitreous luster. Flinteite has a distinct cleavage in one direction, uneven fracture and is brittle. The Mohs hardness is _~_2. Density was not measured due to the presence of inclusions of porous volcanic scoria in the flinteite grains; _D_calc = 2.49 g/cm3. The mineral is optically biaxial (+), α = 1.573(1), β = 1.574(1), γ = 1.576(1) (589 nm), 2_V_estimated = 40(25)°, 2_V_calc = 71° (the discrepancy is probably due to the low birefrigence). It is colorless, non-pleochroic. All bands of the Raman spectrum of flinteite have maxima below 300 cm–1. The intense, narrow band at 294 cm–1 corresponds to Zn–Cl stretching vibrations, bands at 192, 140, and 113 cm–1 correspond to lattice modes, Zn–Cl bending and K–Cl stretching vibrations. No bands indicating the presence of groups with O–H, C–H, C–O, N–H, N–O, B–O, Be–O, and Li–O bonds were observed. The average of 4 electron probe WDS analyses of the holotype [wt% (range)] is: K 24.97 (23.53–25.94), Tl 5.82 (5.27–6.11), Co 0.07 (0–0.29), Zn 22.23 (21.48–23.00), Cl 46.95 (45.76–47.60), total 100.04. The empirical formula based on the sum of all atoms = 7 pfu is: (K1.91Tl0.09)Σ2.00Zn1.04Cl3.96. Compositional variations for all analyzed samples are (wt% range): K (16.34–28.34), Tl (0.31–27.74), Co (0–0.52), Zn (16.70–22.91), Cl (37.20–49.71), Cs (0–2.16), Rb (0–2.44). Flinteite dissolves very easily in H2O at room temperature and is unstable in a humid atmosphere. The most common product of flinteite alteration is cryobostryxite KZnCl3·2H2O. The strongest lines in the powder X-ray diffraction pattern [d Å (I%; hkl)] are: 6.23 (27; 011,020), 5.123 (88; 311,320), 3.629 (98; 611,002), 3.599 (100; 031), 3.133 (35; 022), 3.039 (26; 630), 2.897 (35; 910), 2.688 (46; 911,920). The unit-cell parameters refined from the powder data are: a = 26.827(6), b = 12.405(3), c = 7.252(1) Å, V = 2413 Å3. The crystal structure was solved by direct methods and refined to _R_1 = 0.0686 on the basis of 3516 independent I > 2σ(I) reflections. Flinteite is orthorhombic, _Pna_21, a = 26.8090(10), b = 12.4085(6), c = 7.2512(3) Å, V = 2412.18 Å3, Z = 12. The structure contains three Zn sites centering isolated ZnCl4 tetrahedra and six independent K sites of different coordination. Flinteite is the natural analog of a synthetic non-intrinsic ferroelectric K2ZnCl4 modification with a commensurable structure stable between 145 and 403 K. Flinteite was studied at room temperature and was probably formed as the result of a phase transition when cooling after the extraction of crystals of its protophase from the hot fumaroles. The mineral is named in honor of the famous Russian crystallographer Evgeniy Evgenievich Flint (1887–1975). The holotype is deposited in the Fersman Mineralogical Museum of the Russian Academy of Sciences, Moscow, Russia. D.B.
Fluorchegemite*
I.O. Galuskina, B. Krüger, E.V. Galuskin, T. Armbruster, V.M. Gazeev, R. Włodyka, M. Dulski, and P. Dzierżanowski (2015) Fluorchegemite, Ca7(SiO4)3F2, a new mineral from the edgrewite-bearing endoskarn zone of an altered xenolith in ignimbrites from Upper Chegem caldera, Northern Caucasus, Kabardino-Balkaria, Russia: Occurrence, crystal structure, and new data on the mineral assemblages. Canadian Mineralogist, 53, 325–344.Galuskina IO, Krüger B, Galuskin EV, Armbruster T, Gazeev VM, Włodyka R, Dulski M, Dzierżanowski P. , 2015"Fluorchegemite, Ca7(SiO4)3F2, a new mineral from the edgrewite-bearing endoskarn zone of an altered xenolith in ignimbrites from Upper Chegem caldera, Northern Caucasus, Kabardino-Balkaria, Russia: Occurrence, crystal structure, and new data on the mineral assemblages" Canadian Mineralogist, vol. 53, p. 325–344.
Fluorchegemite (IMA 2011-112), ideally Ca7(SiO4)3F2, is a new mineral from an edgrewite-bearing zone of endoskarn at the contact of a large altered calciferous xenolith within ignimbrites of the Upper Chegem Caldera, Northern Caucasus, Kabardino-Balkaria, Russia. It is associated with larnite, edgrewite, wadalite, eltyubyuite, rondorfite, lakargiite, Th-kerimasite, bultfonteinite, killalaite, hillebrandite, afwillite, trabzonite, and jennite. Fluorchegemite forms either acicular crystals up to 0.1 mm that are irregularly distributed in the host rock and are associated with relatively large edgrewite crystals, or larger acicular crystals up to 0.2 mm that form aggregates replacing larnite in lens-shaped assemblages. Occasionally the crystals are twinned. The new mineral is colorless with a white streak, imperfect cleavage on {010} and irregular fracture. It has a Mohs hardness of ~5½–6. Density was not measured because of inclusions of other minerals, _D_calc = 2.91 g/cm3. Fluorchegemite is colorless nonpleochroic, is optically biaxial (–), with α = 1.610(2), β = 1.6150(2), γ = 1.619(2) (589 nm); 2_V_meas = 80(8)°; 2_V_calc = 84°; X = a, Y = b, Z = c Dispersion of optical axis is weak, r > ν. The main bands in the Raman spectrum (cm–1, s = strong) are: 258, 297 (vibrations of CaO6 octahedra); 410s, 422, 560s (bending vibrations of SiO4 tetrahedra); 817s, 843, 922s (stretching vibrations of SiO4 tetrahedra); 3539, 3548, 3552 (OH-stretching). Fourier-transform IR spectrum show the bands (cm–1, s = strong): 756, 795, 805, 821s, 844s, 889s, 914s, 934s, 962s, 991s, 1031s, 1102, 3552s. Strong bands correspond to asymmetric vibrations in SiO4 tetrahedra. The average of 10 electron probe WDS analyses of the holotype sample is [wt% (range)]: TiO2 0.17 (0.04–0.27), SiO2 29.91 (29.43–30.13), CaO 65.65 (65.31–66.01), MgO 0.04 (0.03–0.05), F 4.43 (4.07–4.97), H2O 0.90, –O=F2 1.88, total 99.22. The formula calculated on the basis of 10 (O+OH+F) apfu is: (Ca7.01Mg0.01)Σ7.02(Si2.98Ti0.014+)Σ2.99O12[F1.40(OH)0.60]Σ2.00. The strongest lines of the X-ray powder diffraction pattern [d Å (I%; hkl)] are: 2.531 (100; 200), 1.905 (90; 227), 2.718 (63; 117), 3.013 (57; 131), 2.991 (56; 116), 3.636 (52; 114), 2.832 (51; 133), 2.699 (46; 134). Fluorchegemite is orthorhombic, space group Pbnm, a = 5.0620(1), b = 11.3917(2), c = 23.5180(3) Å, V = 1356.16(4) Å3, Z = 4. The crystal structure of fluorchegemite was refined on the basis of that of chegemite to _R_1 = 3.98%. Crystal structure of fluorchegemite consists of a framework composed of zigzag chains of four [Ca(O, F, OH)6] octahedra linked by two types of isolated SiO4 tetrahedra. The mineral is named as a fluorine analog of chegemite Ca7(SiO4)3(OH)2. The holotype is deposited in the Fersman Mineralogical Museum of the Russian Academy of Sciences, Moscow, Russia. Yu.U.
Fluor-Tsilaisite*
F. Bosi, G.B. Andreozzi, G. Agrosì, and E. Scandale (2015) Fluor-tsilaisite, NaMn3Al6(Si6O18)(BO3)3(OH)3F, a new tourmaline from San Piero in Campo (Elba, Italy) and new data on tsilaisitic tourmaline from the holotype specimen locality. Mineralogical Magazine, 79, 89–101.Bosi F, Andreozzi GB, Agrosì G, Scandale E. , 2015"Fluor-tsilaisite, NaMn3Al6(Si6O18)(BO3)3(OH)3F, a new tourmaline from San Piero in Campo (Elba, Italy) and new data on tsilaisitic tourmaline from the holotype specimen locality" Mineralogical Magazine, vol. 79, p. 89–101.
Fluor-tsilaisite (IMA 2012-044), ideally NaMn3Al6(Si6O18)(BO3)3(OH)3F, is a new mineral found at Grotta d’Oggi, San Piero in Campo, Elba Island, Italy. The mineral occurs in an aplitic dike of a LCT-type pegmatite in association with quartz, K-feldspar, plagioclase, elbaite, schorl, fluor-elbaite, and tsilaisite. The holotype crystal is a color-zoned tourmaline ~9 mm long and 60 mm2 in basal section with a morphology that consists of elongated {100} and {110} prisms with striated faces, terminated by a prominent {001} pedion and small, minor {101} pyramidal faces. Fluor-tsilaisite is greenish yellow with white streak and a vitreous luster. It is brittle with an imperfect cleavage on {101} and {110}, {001} parting and sub-conchoidal fracture. The Mohs hardness is ~7. The density was not measured; D_calc = 3.134 g/cm3. In transmitted light, fluor-tsilaisite is pleochroic with O = pale greenish yellow > E = very pale greenish yellow. Fluor-tsilaisite is uniaxial (–) with ω = 1.645(5), ∊ = 1.625(5) (white light). The mineral shows no fluorescence in UV light. The average of 10 electron probe WDS analyses is [wt% (St.dev.)]: SiO2 36.65(14), TiO2 0.33(8), B2O3 10.44 (by stoichiometry), Al2O3 35.92(16), MnO 11.63(20), FeO 0.19(6), CaO 0.08(2), Na2O 1.92(4), K2O 0.02(1), Li2O 0.46 (by stoichiometry), F 0.66(9), H2O 2.97 (by structure refinement), –O=F2 0.28, total 100.00. This gives the empirical formula X(Na0.69 ⎕0.29Ca0.02)Σ1.00_Y(Mn1.292+Al1.21Li0.56Ti0.03)Σ6.00_Z_Al6_T_(Si5.98Al0.03)Σ6.01B2.92O27V(OH)3_W_[F0.39(OH)0.25O0.36]Σ1.00. Mn and Fe were considered as divalent cations. Not enough material was available for powder-diffraction measurements, and the calculated spectrum was judged unsuitable for diagnostic identification of the mineral and was therefore not given. Single-crystal X-ray diffraction data collected on a crystal of size 0.20×0.22×0.26 mm refined to _R_1 = 0.036 for 3496 unique reflections shows fluor-tsilaisite is rhombohedral, space group R_3_m, a = 15.9398(6), c = 7.1363(3) Å, V = 1570.25 Å3, Z = 3. Fluor-tsilaisite is related to tsilaisite through the substitution _W_F ↔ W(OH) and with fluor-elbaite through the substitution Y(Al + Li) ↔ 2_Y_Mn2+. The new mineral appears to be a stepwise intermediate during tourmaline evolution from tsilaisite to fluor-elbaite. The name is derived from the tsilaisite root of the tourmaline supergroup. The holotype of fluor-tsilaisite is deposited in the “Museo di Scienze della Terra, settore Mineralogico Petrografico Carlo Lorenzo Garavelli”, Università di Bari, Bari, Italy. O.C.G.
Gatedalite*
U. Hålenius and F. Bosi (2015) Gatedalite, Zr(Mn2+Mn43+)SiO12, a new mineral species of the braunite group from Långban, Sweden. Mineralogical Magazine, 79, 625–634.Hålenius U, Bosi F. , 2015"Gatedalite, Zr(Mn2+Mn43+)SiO12, a new mineral species of the braunite group from Långban, Sweden" Mineralogical Magazine, vol. 79, p. 625–634.
Gatedalite (IMA 2013-091), ideally Zr(Mn2+Mn43+)SiO12, is a new mineral found at the Långban Mn-Fe oxide deposit, Värmland, central Sweden. It is found in hausmannite-impregnated skarn with jacobsite, Mn-calcite, tephroite, Mn-phlogopite, långbanite, pinakiolite, and oxyplumboroméite. The mineral occurs as irregularly rounded anhedral grains up to 60 µm. Gatedalite is gray and opaque with submetallic luster, shows no cleavage or parting, and is brittle. The hardness and density could not be determined due to small grain size and extreme scarcity of material; _D_calc = 4.783 g/cm3. The mineral shows very weak anisotropy and bireflectance and no pleochroism. Reflectance values for COM wavelengths [_R_min, _R_max % (nm)] are: 20.0, 19.1 (470); 19.1, 18.1 (546); 18.9, 18.0 (589); 18.7, 17.4 (650). The average of 4 electron probe WDS analyses is [wt% (range)]: SiO2 9.82 (9.53–10.10), ZrO2 9.97 (9.44–11.10), Al2O3 0.05 (0.05–0.06), Mn2O3 57.90 (56.31–59.26), Fe2O3 7.81 (7.35–8.28), Ce2O3 0.28 (0.16–0.37), MgO 3.20 (2.99–3.52), CaO 0.16 (0.14–0.20), MnO 11.34 (10.67–11.90), ZnO 0.13 (0.00–0.19), Na2O 0.01 (0.00–0.02), total 100.68. This gives the empirical formula (Zr0.494+Mn0.472+Ca0.02Zn0.01Ce0.013+)Σ1.00(Mn4.443+Fe0.593+Mn0.502+Mg0.48Al0.01)Σ6.02Si0.99O12 based on 12 O apfu. The analyzed Mn content was split into Mn2O3 and MnO on the basis of electro neutrality and 12 O apfu. Not enough material was available to measure powder XRD data; the strongest lines in the calculated X-ray powder-diffraction pattern [_d_calc (Å) (_I_calc%; hkl)] are: 2.730 (100; 224), 2.367 (12; 040), 1.6735 (12; 440), 1.6707 (29; 048), 1.4267 (16; 264). Single-crystal X-ray diffraction data collected on a crystal of size 0.04×0.04×0.06 mm refined to _R_1 = 0.0509 for 1339 unique reflections shows gatedalite is tetragonal, space group _I_41/acd, with the unit-cell parameters a = 9.4668(6) Å, c = 18.8701(14) Å, V = 1691.1 Å3, and Z = 8. Gatedalite is a member of the braunite group (general formula AB6SiO12) and is related to braunite via (Zr4+ + Mn2+) → 2Mn3+ substitution. The mineral is named in honor of amateur mineralogist Kjell Gatedal (b. 1947) from Nora, Örebro, Sweden, for his contributions to the mineralogy of Långban-type deposits. The holotype specimen of gatedalite is deposited in the Swedish Museum of Natural History, Stockholm, Sweden. O.C.G.
Kononovite*
I.V. Pekov, M.G. Krzhizhanovskaya, V.O. Yapaskurt, D.I. Belakovskiy, N.V. Chukanov, I.S. Lykova, and E.G. Sidorov (2015) Kononovite, NaMg(SO4)F, a new mineral from the Arsenatnaya fumarole, Tolbachik volcano, Kamchatka, Russia. European Journal of Mineralogy, 27, 575–580.Pekov IV, Krzhizhanovskaya MG, Yapaskurt VO, Belakovskiy DI, Chukanov NV, Lykova IS, Sidorov EG. , 2015"Kononovite, NaMg(SO4)F, a new mineral from the Arsenatnaya fumarole, Tolbachik volcano, Kamchatka, Russia" European Journal of Mineralogy, vol. 27, p. 575–580.
Kononovite, (IMA 2013-116), ideally NaMg(SO4)F is a new sulfate member of the durangite group from the Arsenatnaya fumarole at the Second scoria cone of the Northern Breakthrough of the Great Tolbachik Fissure Eruption, Tolbachik volcano, Kamchatka, Russia. Kononovite found in a single specimen in close association with langbeinite, hematite, anglesite, and euchlorine. Temperatures measured immediately after uncovering of the fumarole camera containing kononovite vary from 360 to 390 °C. Admixed uklonskovite is a product of the kononovite supergene alteration. The new mineral occurs as prismatic to thick tabular crystals up to 0.04×0.06×0.1 mm, isolated or, more typically, forming clusters or interrupted crusts up to several square centimeters in area and up to 0.05 mm thick overgrowing basalt scoria. Kononovite is white, transparent in tiny grains and translucent in blocky crystals. It has white streak and vitreous luster. Kononovite is brittle but with signs of weak plasticity. Mohs hardness is ~3. The fracture is uneven. _D_meas = 2.91(1) g/cm3 (by flotation in heavy liquids), _D_calc = 2.945 g/cm3. The mineral is non-fluorescent under UV light or an electron beam. In plane-polarized light kononovite is colorless, nonpleochroic. It is optically biaxial (+), α = 1.488(2), β = 1.491(2), γ = 1.496(2) (589 nm), 2_V_meas = 75(5)°, and 2_V_calc = 76°. The IR spectrum of kononovite shows absorption bands (cm–1, w = weak band, s = strong band, sh = shoulder) at 2132w (combination mode of symmetric and asymmetric vibrations of SO42– anions), 1133s [ν3(_F_2) = asymmetric stretching vibrations of SO42– anions], 1010 [ν1(_A_1) = symmetric stretching vibrations of SO42– anions], 635s, 612s [ν4(_F_2) = bending vibrations of SO42– anions], 544, 505w, 461 (lattice modes involving Mg···O and Mg···F stretching vibrations). Bands corresponding to NH4+, CO32− and NO3− groups (the range 1300–1500 cm–1) were not observed. The average of 4 electron probe WDS analyses is [wt% (range)]: Na2O 18.68 (17.82–19.18), K2O 0.14 (0.00–0.31), MgO 24.77 (24.03–25.43), ZnO 0.28 (0.00–0.65), PbO 0.10 (0.00–0.41), SO3 48.44 (47.40–49.14), F 11.82 (11.45–12.01), Cl 0.12 (0.00–0.49), –O=(F, Cl)2 5.00, total 99.35. The empirical formula calculated on the basis of 5 (O+F) pfu is: Na0.99K0.01Mg1.01Zn0.01S0.99O3.97F1.02Cl0.01. The strongest X-ray powder diffraction lines [d Å (I%; hkl)] are: 4.766 (38; 111), 3.567 (33; 021), 3.233 (82; 112), 3.210 (55; 002), 3.041 (100; 200), 2.589 (53; 130), 2.571 (38; 022), 2.269 (33; 131). The monoclinic unit-cell parameters refined from the powder data are: a = 6.662(2), b = 8.584(3), c = 7.035(2) Å, β = 114.06(3)°, V = 367.4 Å3, Z = 4. Kononovite is isostructural with fluoro(hydroxyl)phosphates and fluorarsenates of the durangite group: isokite CaMg(PO4)F, lacroixite NaAl(PO4)F, panasqueiraite Ca(Mg, Fe)(PO4)(OH, F), durangite NaAl(AsO4)F, maxwellite NaFe3+(AsO4)F, and tilasite CaMg(AsO4)F. The name kononovite (Cyrillic: кононовит) honors the Russian mineralogist Oleg Vasil’evich Kononov (b. 1932), a specialist in general and technological mineralogy, teacher of mineralogy at Lomonosov Moscow State University for more than 50 years. The holotype is deposited in the Fersman Mineralogical Museum of the Russian Academy of Sciences, Moscow, Russia. F.C.
Mendigite*
N.V. Chukanov, S.M. Aksenov, R.K. Rastsvetaeva, K.V. Van, D.I. Belakovskiy, I.V. Pekov, V.V. Gurzhiy, W. Schüller, and B. Ternes (2015) Mendigite, Mn2Mn2MnCa(Si3O9)2, a new mineral species of the bustamite group from the Eifel Volcanic Region, Germany. ZapiskiRossiiskogo Mineralogicheskogo Obshchestva, 144, 48–60 (in Russian, English abstract); Geology of Ore Deposits, 57, 721–731 (in English).Chukanov NV, Aksenov SM, Rastsvetaeva RK, Van KV, Belakovskiy DI, Pekov IV, Gurzhiy VV, Schüller W, Ternes B. , 2015"Mendigite, Mn2Mn2MnCa(Si3O9)2, a new mineral species of the bustamite group from the Eifel Volcanic Region, Germany" ZapiskiRossiiskogo Mineralogicheskogo Obshchestva, vol. 144, p. 48–60.
Mendigite (IMA 2014-007), ideally Mn2Mn2MnCa(Si3O9)2, is a new mineral discovered in the In den Dellen near Mendig, Laacher Lake area, Eifel Mountains, Rhineland-Palatinate (Rheinland-Pfalz), Germany. The new mineral was found in sanidinite in the operating pumice quarry in association with sanidine, nosean, rhodonite, tephroite, magnetite, and a pyrochlore-group mineral. Mendigite forms imperfect long-prismatic crystals up to 0.1×0.2×2.5 mm in size, flattened on {001}; occasionally crystals form polysynthetic twins parallel to (100). The mineral is dark brown, has a brown streak, vitreous luster, perfect cleavage on {001}; D_calc = 3.56 g/cm3. Mendigite is biaxial (–), with β = 1.782(5), γ = 1.796(5) (589 nm), 2_V_obs = 50(10)°; α was not measured due to a perfect cleavage, but was estimated to be 1.722 based on β, γ, and 2_V values. Dispersion of optical axis is medium, r > ν. Mendigite is non-pleochroic, with extinction angle of about 4–5° relative to [100]. The bands in IR spectrum (cm–1, s = strong, sh = shoulder) are: 1088s, 1030s, 945s, 907s (Si-O stretching vibrations); 694, 655, 564 (O-Si-O bending vibrations); 515, 461s, 445, 425sh (lattice modes involving Si-O-Si bending and _M_···O stretching vibrations, where M = Mn, Fe, Ca). The average of 4 electron probe EDS analyses [wt%, (range)] is: SiO2 43.80 (43.24–44.54), Al2O3 1.08 (0.87–1.28), Fe2O3 4.42 (4.15–4.70), Mn2O3 2.91, MnO 37.47 (39.37–40.80, for total Mn calculated as MnO), CaO 10.78 (10.11–10.92), MgO 0.36 (0.25–0.49), total 100.82. The amount of Mn2O3 was calculated taking into account structural data and charge balance. The formula calculated on the basis of 12 (Mg+Ca+Mn+Al+Fe+Si) cations pfu is: (Ca1.47Mn4.032+Mg0.07Mn0.283+Fe0.153+)Σ6.00[(Si5.57Fe0.273+Al0.16)Σ6.00O18]. The strongest lines of the X-ray powder diffraction pattern [d Å (I%; hkl)] are: 3.72 (32; 020), 3.40 (20; 002,021), 3.199 (25; 012), 3.000 (26; 012,120), 2.885 (100; 221,211,12 1), 2.691 (21; 222,210), 2.397 (21; 022,211,203,031), 1.774 (37; 412,321). The crystal structure of mendigite was determined with the “charge flipping” procedure and refined to _R_1 = 5.59%. The mineral is triclinic, _P_1, a = 7.0993(4), b = 7.6370(5), c = 7.7037(4) Å, α = 79.58(1), β = 62.62(1), γ = 76.47(1)°, V = 359.29(4) Å3, Z = 1. Mendigite is isostructural with bustamite and ferrobustamite. The crystal structure of mendigite is formed by bands of M polyhedra that are three-polyhedra wide, and wollastonite-type chains of SiO4 tetrahedra. Each band of M polyhedra is linked to two chains of SiO4 tetrahedra on both sides of the band. The type specimen is deposited in the Fersman Mineralogical Museum, Russian Academy of Sciences, Moscow, Russia. Yu.U.
Nabimusaite*
E.V. Galuskin, F. Gfeller, T. Armbruster, I.O. Galuskina, Y. Vapnik, M. Murashko, R. Włodyka, and P. Dzierżanowski (2015) New minerals with a modular structure derived from hatrurite from the pyrometamorphic Hatrurim Complex. Part I. Nabimusaite, KCa12(SiO4)4(SO4)2O2F, from larnite rocks of Jabel Harmun, Palestinian Autonomy, Israel. Mineralogical Magazine, 79, 1061–1072.Galuskin EV, Gfeller F, Armbruster T, Galuskina IO, Vapnik Y, Murashko M, Włodyka R, Dzierżanowski P. , 2015"New minerals with a modular structure derived from hatrurite from the pyrometamorphic Hatrurim Complex. Part I. Nabimusaite, KCa12(SiO4)4(SO4)2O2F, from larnite rocks of Jabel Harmun, Palestinian Autonomy, Israel" Mineralogical Magazine, vol. 79, p. 1061–1072.
Nabimusaite (IMA 2012-057), ideally KCa12(SiO4)4(SO4)2O2F, has been discovered in pyrometamorphic rocks of the Hatrurim Complex (“Mottled zone”) on Jabel (Mount) Harmun near the village Nabi Musa, Judea Desert, West Bank, Palestinian Autonomy. Later this mineral was found as a rock-forming component at many locations of larnite pyrometamorphic rocks of the Hatrurim Complex in the Judean Mountains (Ma’ale-Adummin and Nahal Darga localities) and in the Negev Desert (Har Parsa Mountain), Israel. Nabimusaite formation related to a high-temperature syn-pyrometamorphic alteration of primary ye’elimite-larnite rocks during combustion events as a result of the reaction of potassium-enriched, sulfate-bearing melt with larnite and ellestadite. The new mineral occurs in larnite-ye’elimite nodules locally termed “pseudo-conglomerates.” Other associated minerals are brownmillerite, P-fluorellestadite, fluormayenite-fluorkyuygenite, and less commonly gehlenite, ternesite, jasmundite, periclase, oldhamite, covellite, dzierżanowskite, shulamitite, magnesioferrite, and spinel. Nabimusiate is usually developed after fluorellestadite, but also replaces larnite. Along the rims, nabimusaite grains are substituted by a mixture of uncharacterized Ca hydrosilicates, minerals of the ettringite group and barite. Nabimusaite forms xenomorphic, poikilitic crystals generally 0.1–0.2 mm, rarely up to 0.5 mm, filled with inclusions of larnite and ye’elmite. The mineral is colorless, transparent with a white streak and a vitreous luster. No fluorescence in UV light was observed. It is brittle and has pronounced parting and imperfect cleavage on {001}. The micro-indentation hardness VHN50 = 420 (370–500) kg/mm2 corresponds to ~5 of Mohs scale. Density was not measured due to numerous inclusions in the grains; D_calc = 3.119 g/cm3. Nabimusaite is uniaxial (−), ω = 1.644(2), ∊ = 1.640(2) (589 nm), nonpleochroic. The main bands in the Raman spectrum (cm−1) are: 129 (Ba–O vibration); 403 (ν2SiO44–); 463 (ν2SO42–); 524 and 563 (ν4SiO44–); 637 (ν4SO42–); 831, 849, and 885 (ν1SiO44–); 930 and 948 (ν3SiO44–); 993 (ν1SO42–); 1121 (ν3SO42–). The average of 24 electron probe WDS analysis of the holotype sample [wt% (range)] is: SO3 13.85 (12.59–14.70), V2O5 <0.07, P2O5 1.80 (1.51–2.21), TiO2 0.10 (0.04–0.21), SiO2 18.44 (17.93–18.85), Al2O3 0.34 (0.25–0.48), BaO 3.60 (2.01–4.91), SrO 0.21 (0.13–0.29), Fe2O3 0.13 (0–0.28), CaO 57.95 (56.39–59.21), MgO 0.10 (0.06–0.13), ZnO <0.06, K2O 2.52 (2.05–3.02), Na2O 0.14 (0.08–0.20), F 1.05 (0.53–1.54), –O=F2 0.44, total 99.79. The empirical formula calculated on the basis of (O+F) = 27 apfu is: (K0.62Ba0.27Na0.05Mg0.03Sr0.02)Σ0.99Ca11.98(Si3.56P0.29Al0.08Fe0.023+Ti0.014+)Σ3.96S2.01O26.36F0.64. Nabimusaite is characterized by a variable chemical composition. Some spots in nabimusaite grains are enriched with Ba up to composition (Ba0.55K0.38Na0.05Mg0.03)Σ1.01Ca11.97(Si3.54P0.23Al0.17Fe0.023+Ti0.044+)Σ4(S1.87P0.14)Σ2.01O26.52F0.48, which is a potentially new mineral—Ba analog of nabimusaite (currently approved by IMA CNMNC as dargaite D.B.). Due to difficulties in the selection of uncontaminated grains the powder X-ray diffraction data have been calculated from the refined crystal structure. The strongest X-ray calculated powder diffraction lines [_d_calc Å (_I_calc%; _hkl_)] are: 3.595 (52; 110), 3.105 (97; 021), 2.829 (71; 119), 2.753 (97; 027), 2.750 (89; 0.0.15), 2.140 (50; 2.0.14), 1.986 (46; 0.2.16), 1.798 (100; 220). The crystal structure has been solved and refined to _R_1 = 0.0416 for 547 _I_ > 2σ_I unique reflections. The mineral is trigonal, space group R_3_m, a = 7.1905(4), c = 41.251(3) Å, V = 1847.1 Å3, Z = 3. The nabimusaite structure is a representative of the intercalated antiperovskite type. It may be derived from the structure of hatrurite, also known as the clinker phase “alite” (Ca3SiO5). Both structures are characterized by triplets of face-sharing, antiperovskite type anion-centred [(O, F)Ca6] octahedra of composition [FO2Ca12]19+ in nabimusaite. Compared to hatrurite the antiperovskite modules [FO2Ca12(SiO4)4]3+ in nabimusaite are intercalated with K(SO4)23– slices. Tetrahedral tips of SiO4 tetrahedra between the triplets within the antiperovskite layer in hatrurite all point in the same direction along [001], while in nabimusaite (as well as in nabimusaite-group minerals zadovite and aradite) the Si(1) and Si(2) tetrahedra point in opposite directions. The Si(1) sites are fully occupied by Si and P is accumulated at the Si(2) sites. The crystal structure of nabimusaite corresponds to the synthetic phase KCa12(SiO4)4(SO4)2O2F. The mineral is named for its type locality near the village of Nabi Musa. Type material is deposited in the Museum of Natural History of Bern, Switzerland. D.B.