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Ekplexite (Nb,Mo)S2·(Mg1−xAlx)(OH)2+x, kaskasite (Mo,Nb)S2·(Mg1−xAlx)(OH)2+x and manganokaskasite (Mo,Nb)S2·(Mn1−xAlx)(OH)2+x, three new valleriite-group mineral species from the Khibiny alkaline complex, Kola peninsula, Russia

Published online by Cambridge University Press:  05 July 2018

I. V. Pekov ,
V. O. Yapaskurt ,
Y. S. Polekhovsky ,
M. F. Vigasina  and
O. I. Siidra
I. V. Pekov*
Affiliation:
Faculty of Geology, Moscow State University, Vorobievy Gory, 119991 Moscow, Russia
V. O. Yapaskurt
Affiliation:
Faculty of Geology, Moscow State University, Vorobievy Gory, 119991 Moscow, Russia
Y. S. Polekhovsky
Affiliation:
Faculty of Geology, St Petersburg State University, University Embankment 7/9, 199034 St Petersburg, Russia
M. F. Vigasina
Affiliation:
Faculty of Geology, Moscow State University, Vorobievy Gory, 119991 Moscow, Russia
O. I. Siidra
Affiliation:
Faculty of Geology, St Petersburg State University, University Embankment 7/9, 199034 St Petersburg, Russia
*
E-mail: [email protected]
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Abstract

Three new valleriite-group minerals, ekplexite (Nb,Mo)S2·(Mg1−xAlx)(OH)2+x, kaskasite (Mo,Nb)S2·(Mg1−xAlx)(OH)2+x and manganokaskasite (Mo,Nb)S2·(Mn1−xAlx)(OH)2+x are found at Mt Kaskasnyunchorr, Khibiny alkaline complex, Kola Peninsula, Russia. They occur in fenite consisting of orthoclase−anorthoclase and nepheline with fluorophlogopite, corundum, pyrrhotite, pyrite, rutile, monazite-(Ce), graphite, edgarite, molybdenite, tungstenite, alabandite, etc. Ekplexite forms lenticular nests up to 0.2 mm × 1 mm × 1 mm consisting of near-parallel, radiating or chaotic aggregates of flakes. Kaskasite and manganokaskasite mainly occur as flakes and their near-parallel ‘stacks’ (kaskasite: up to 0.03 mm × 1 mm × 1.5 mm; manganokaskasite: up to 0.02 mm × 0.5 mm × 1 mm) epitaxially overgrow Ti-bearing pyrrhotite partially replaced by Ti-bearing pyrite. All three new minerals are opaque, ironblack, with metallic lustre. Cleavage is {001} perfect and mica-like. Flakes are very soft, flexible and inelastic. Mohs hardness is ∼1. D(calc.) = 3.63 (ekplexite), 3.83 (kaskasite) and 4.09 (manganokaskasite) g cm−3. In reflected light all these minerals are grey, without internal reflections. Anisotropism and bireflectance are very strong and pleochroism is strong. The presence of OH groups and an absence of H2O molecules are confirmed by the Raman spectroscopy data. Chemical data (wt.%, electron probe) for ekplexite, kaskasite and manganokaskasite, respectively, are: Mg 6.25, 5.94, 0.06; Al 4.31, 3.67, 3.00; Ca 0.00, 0.04, 0.00; V 0.86, 0.16, 0.15; Mn 0.00, 0.23, 11.44; Fe 0.44, 1.44, 2.06; Nb 18.17, 13.39, 14.15; Mo 15.89, 23.18, 20.08; W 8.13, 7.59, 9.12; S 27.68, 27.09, 24.84; O 16.33, 15.66, 13.36; H (calc.) 1.03, 0.99, 0.89; total 99.09, 99.08, 99.15. The empirical formulae calculated on the basis of 2 S a.p.f.u. are: ekplexite: (Nb0.45Mo0.38W0.10V0.04)S0.97S2· (Mg0.60Al0.37Fe0.02)S0.99(OH)2.36; kaskasite: (Mo0.57Nb0.34W0.10V0.01)S1.02S2· (Mg0.58Al0.32Fe0.06Mn0.01)S0.97(OH)2.32; manganokaskasite: (Mo0.54Nb0.39W0.13V0.01)S1.07S2· (Mn0.54Al0.29Fe0.10Mg0.01)S0.94(OH)2.28. All three minerals are trigonal, space groups Pm1, P3m1 or P321, one-layer polytypes (Z = 1). Their structures are non-commensurate and consist of the MeS2-type (Me = Nb, Mo, W) sulfide modules and the brucite-type hydroxide modules. Parameters of the sulfide (main) sub-lattices (a, c in Å, V in Å3) are: 3.262(2), 11.44(2), 105.4(4) (ekplexite); 3.220(2), 11.47(2), 102.8(4) (kaskasite); 3.243(3), 11.61(1), 105.8(3) (manganokaskasite). Parameters of the hydroxide sub-lattices (a, c in Å, V in Å3) are: 3.066(2), 11.52(2), 93.8(4) (ekplexite); 3.073(2), 11.50(2), 94.0(4) (kaskasite); 3.118(3), 11.62(1), 97.9(2) (manganokaskasite). Ekplexite was named from the Greek word έκπληξη meaning surprise, for its exotic combination of major chemical constituents, kaskasite after the discovery locality and manganokaskasite as a Mn analogue of kaskasite.

Keywords

ekplexitekaskasitemanganokaskasitenew mineralvalleriite grouphydroxide-sulfidehybrid mineralnon-commensurate structureniobiummolybdenumfenitealkaline rockKhibinyKola peninsula
Type
Research Article
Information
Mineralogical Magazine , Volume 78 , Issue 3 , June 2014 , pp. 663 - 679
Copyright
Copyright © The Mineralogical Society of Great Britain and Ireland 2014

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References

Barkov, A.Y., Laajoki, K.V.O., Men’shikov, Y.P., Alapieti, T.T. and Sivonen, S.J. (1997) First terrestrial occurrence of titanium-rich pyrrhotite, pyrite and marcasite in a fenitized xenolith from the Khibina alkaline complex, Russia. The Canadian Mineralogist, 35, 875–885.Google Scholar
Barkov, A.Y., Martin, R.F., Men’shikov, Y.P., Savchenko, Y.E., Thibault, Y. and Laajoki, K.V.O. (2000a) Edgarite, FeNb3S6, the first natural niobiumrich sulfide from the Khibina alkaline complex, Russian Far North: evidence for chalcophile behavior of Nb in a fenite. Contributions to Mineralogy and Petrology, 138, 229–236.CrossRefGoogle Scholar
Barkov, A.Y., Martin, R.F., Poirier, G. and Men’shikov, Y.P. (2000b) Zoned tungstenoan molybdenite from a fenitized megaxenolith in the Khibina alkaline complex, Kola Peninsula, Russia. The Canadian Mineralogist, 38, 1377–1385.CrossRefGoogle Scholar
Barkov, A.Y., Fleet, M.E., Martin, R.F. and Men’shikov, Y.P. (2006) Sr-Na-REE titanates of the crichtonite group from a fenitized megaxenolith, Khibina alkaline complex, Kola Peninsula, Russia: first occurrence and implications. European Journal of Mineralogy, 18, 493–502.CrossRefGoogle Scholar
Browning, L.B. and Bourcier, W.L. (1996) Tochilinite: a sensitive indicator of alteration conditions on the CM asteroidal parent body. Lunar and Planetary Science, 27, 171.Google Scholar
Dawson, P., Hadfield, C.D. and Wilkinson, G.R. (1973) The polarized IR and Raman spectra of Mg(OH)2 and Ca(OH)2. Journal of Physics and Chemistry of Solids, 34, 1217–1225.CrossRefGoogle Scholar
Drábek, M., Hybner, J., Rieder, M. and Böhmová, V. (2010) The system Fe–Nb–S and its geological implications. The Canadian Mineralogist, 48, 1059–1068.CrossRefGoogle Scholar
El Goresy, A., Nagel, K. and Ramdohr, P. (1978) Fremdlinge and their noble relatives. Proceedings of the Lunar and Planetary Science Conference, Houston, Texas, 9, 1279–1303.Google Scholar
Evans, H.T., Jr. and Allmann, R. (1968) The crystal structure and crystal chemistry of valleriite. Zeitschrift für Kristallographie, 127, 73–93.CrossRefGoogle Scholar
Evans, H.T., Jr., Milton, C., Chao, E.C.T., Adler, I., Mead, C., Ingram, B. and Berner, R.A. (1964) Valleriite and the new iron sulfide, mackinawite. United States Geological Survey Professional Paper 475-D, D64–D69.Google Scholar
Evstigneeva, T.L., Genkin, A.D., Sandomirskaya, S.M. and Trubkin, N.V. (1992) Vyalsovite, a new sulfidehydroxide of iron, calcium and aluminum. American Mineralogist, 77, 201–206.Google Scholar
Gressier, P., Rabu, P., Meerschaut, A., Guemas, L. and Rouxel, J. (1997) Misfit layer compounds family (MS)nTS2 (M = Sn, Pb, Bi, rare earth element; T = Nb, Ta; n = 1.08–1.19). Phase Transitions, 30, 39–47.CrossRefGoogle Scholar
Huhma, M., Vuorelainen, Y., Hakli, T.A. and Papunen, H. (1973) Haapalaite, a new nickel-iron sulfide of the valleriite type from East Finland. Bulletin of the Geological Society of Finland, 45, 103–106.CrossRefGoogle Scholar
Jambor, J.L. (1976) New occurrences of the hybrid sulfide tochilinite. Geological Survey of Canada Paper, 76-1B, 65-69.Google Scholar
Jellinek, F., Brauer, G. and Müller, H. (1960) Molybdenum and niobium sulfides. Nature, 185, 376–377.CrossRefGoogle Scholar
Kalikhman, V.L. and Golubnichaya, A.A. (1983) Structure of intermediate phases of quasibinary systems of disulfides of W, Mo and Nb. Soviet Physics, Crystallography, 28, 474–475.Google Scholar
Kalikhman, V.L. and Umansky, Y.A. (1972) Chalcogenides of transition metals with layered structure and features of occupancy of their Brillouin zone. Uspekhi Fizicheskikh Nauk, 108, 503–528.[in Russian].CrossRefGoogle Scholar
Lafond, A., Deudon, C., Meerschaut, A., Palvadeau, P., Moëlo, Y. and Briggs, A. (1999) Structure determination and physical properties of the misfit layered compound (Pb2FeS3)0.58·NbS2. Journal of Solid State Chemistry, 142, 461–469.CrossRefGoogle Scholar
Makeev, A.B., Evstigneeva, T.L., Troneva, N.V., Vyal’sov, L.N., Gorshkov, A.I. and Trubkin, N.V. (1984) Yushkinite, V1-xS·[n(Mg,Al)(OH)2] – a new mineral. Mineralogicheskii Zhurnal, 6(3), 91–97 [in Russian].Google Scholar
Makovicky, E. (2006) Crystal structures of sulfides and other chalcogenides. Pp. 7–125 in: Sulfide Mineralogy and Geochemistry (D.J. Vaughan, editor). Reviews in Mineralogy & Geochemistry, 61. Mineralogical Society of America and the Geochemical Society, Chantilly, Virginia, USA.CrossRefGoogle Scholar
Men’shikov, Y.P. (1978) Corundum mineralization in the Khibiny alkaline complex. Doklady Akademii Nauk SSSR, 243, 1247–1249.[in Russian].Google Scholar
Moëlo, Y., Rouer, O., Cario, L. and Cervelle, B. (1999) Re-examination of yushkinite: chemical composition, optical properties and interlayer charge transfer. Mineralogical Magazine, 63, 879–889.CrossRefGoogle Scholar
Nader, A., Briggs, A. and Gotoh, Y. (1997) Superconductivity in the misfit layer compounds (BiSe)1.11(NbSe2) and (BiS)1.11(NbS2). Solid State Communications, 101, 149–153.CrossRefGoogle Scholar
Organova, N.I. (1989) Crystal Chemistry of Incommensurate and Modulated Mixed-Layer Minerals. Nauka, Moscow [in Russian].Google Scholar
Organova, N.I., Genkin, A.D., Drits, V.A., Molotkov, S.P., Kuz’mina, O.V. and Dmitrik, A.L. (1971) Tochilinite, a new sulfide-hydroxide of iron and magnesium. Zapiski V sesoyuznogo Mineralogicheskogo Obshchestva, 100, 477–487.[in Russian].Google Scholar
Organova, N.I., Drits, V.A. and Dmitrik, A.L. (1972) Structural study of tochilinite. Part I. The isometric variety. Soviet Physics, Crystallography, 17, 761–767.Google Scholar
Pekov, I.V., Chukanov, N.V., Boldyreva, M.M. and Dubinchuk, V.T. (2006) Wilhelmramsayite, Cu3FeS3·2H2O, a new mineral from the Khibiny massif, Kola Peninsula. Zapiski Rossiiskogo Mineralogicheskogo Obshchestva, 135(1), 38–48 [in Russian].Google Scholar
Pekov, I.V., Sereda, E.V., Polekhovsky, Y.S., Britvin, S.N., Chukanov, N.V., Yapaskurt, V.O. and Bryzgalov, I.A. (2013a) Ferrotochilinite, 6FeS·5Fe(OH)2, a new mineral from the Oktyabr’sky deposit, Noril’sk district, Siberia, Russia. Geology of Ore Deposits, 55(7), 567–574 [translated from: Zapiski Rossii skogo Mineralogicheskogo Obshchestva, 2012, 141, 1–11..Google Scholar
Pekov, I.V., Sereda, E.V., Yapaskurt, V.O., Polekhovsky, Y.S., Britvin, S.N. and Chukanov, N.V. (2013b) Ferrovalleriite, 2(Fe,Cu)S·1.5Fe(OH)2: validation as a mineral species and new data. Geology of Ore Deposits, 55(8), 637–647 [translated from: Zapiski Rossiiskogo Mineralogicheskogo Obshchestva, 2011, 141, 29–43].CrossRefGoogle Scholar
Schutte, W.J., de Boer, J.L. and Jellinek, F. (1987) Crystal structures of tungsten disulfide and diselenide. Journal of Solid State Chemistry, 70, 207–209.CrossRefGoogle Scholar
Sugaki, A., Shima, H., Kitakaze, A. and Mizota, T. (1981) Hydrothermal synthesis of nukundamite and its crystal structure. American Mineralogist, 66, 398–402.Google Scholar
Wang, S.-L. and Johnston, C.T. (2000) Assignment of the structural OH stretching bands at gibbsite. American Mineralogist, 85, 739–744.CrossRefGoogle Scholar
Wiegers, G.A., Meetsma, A., Haange, R.J., Van Smaalen, S., de Boer, J.L., Meerschaut, A., Rabu, P. and Rouxel, J. (1990) The incommensurate misfit layer structure of (PbS)1.14·NbS2, “PbNbS3”, and (LaS)1.14·NbS2, “LaNbS3”: an X-ray diffraction study. Acta Crystallographica, B46, 324–332.CrossRefGoogle Scholar
Yakovleva, O.S., Pekov, I.V., Bryzgalov, I.A. and Men’shikov, Y.P. (2010) Chalcogenide mineralization in the alumina-rich fenites of the Khibiny alkaline complex (Kola Peninsula, Russia). New Data on Minerals, 45, 33–49.Google Scholar