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Mavlyanovite, Mn5Si3: a new mineral species from a lamproite diatreme, Chatkal Ridge, Uzbekistan

Published online by Cambridge University Press:  05 July 2018

R. G. Yusupov
Affiliation:
Samarkandskaya-Darbaza st., 2A, 26, Tashkent, Uzbekistan, 100021
C. J. Stanley*
Affiliation:
Department of Mineralogy, Natural History Museum, Cromwell Road, London SW7 5BD, UK
M. D. Welch
Affiliation:
Department of Mineralogy, Natural History Museum, Cromwell Road, London SW7 5BD, UK
J. Spratt
Affiliation:
Department of Mineralogy, Natural History Museum, Cromwell Road, London SW7 5BD, UK
G. Cressey
Affiliation:
Department of Mineralogy, Natural History Museum, Cromwell Road, London SW7 5BD, UK
M. S. Rumsey
Affiliation:
Department of Mineralogy, Natural History Museum, Cromwell Road, London SW7 5BD, UK
R. Seltmann
Affiliation:
Department of Mineralogy, Natural History Museum, Cromwell Road, London SW7 5BD, UK
E. Igamberdiev
Affiliation:
Toitepa, Tashkent oblast, Uzbekistan
*

Abstract

Mavlyanovite, ideally Mn5Si3, is a new mineral from a lamproite diatreme close to the upper reaches of the Koshmansay river, Chatkal ridge, Uzbekistan. It occurs together with unnamed manganese siliciphosphide and manganese silicicarbide minerals in round to ovoid segregations, up to 10 cm in diameter, in volcanic glass. Segregations of hexagonal prismatic mavlyanovite up to 1–2 mm occur in interstices in the matrix and tiny inclusions (1–2 μm) of alabandite and khamrabaevite occur within mavlyanovite. It is opaque with a metallic lustre, has a dark-grey streak, is brittle with a conchoidal fracture and a near-perfect basal cleavage. VHN100 is 1029–1098 kg/mm2 (Mohs hardness ~7). In plane-polarized reflected light, mavlyanovite is a pale-brownish-grey against the accompanying unnamed manganese silicicarbide (white). Reflectance values and colour data are tabulated. Average results of 19 electronmicroprobe analyses give Mn70.84, Fe 6.12, Si 22.57, Ti 0.15, P 0.18, total 99.86 wt.% leading to an empirical formula of (Mn4.66Fe0.40)5.06(Si2.91Ti0.01P0.02)2.94 based on8 a.p.f.u. The calculated density is 6.06 g/cm3, (on the basis of the empirical formula and unit-cell parameters from the structure determination). Mavlyanovite is hexagonal (P63/mcm) with a 6.8971(7), c 4.8075(4) Å, V 198.05(3) Å3 and Z = 2. The structure has been determined and refined to R1 = 0.017, wR2 = 0.044, GoF = 1.16. Mavlyanovite is the naturally-occurring analogue of synthetic Mn5Si3 which is the parent aristotype structure of the Nowotny intermetallic phases studied extensively by the material-science community. It is also the Mn-dominant analogue of xifengite Fe5Si3. The mineral name honours Academician Gani Arifkhanovich Mavlyanov (1910–1988), for his contributions to the understanding of the geology of Uzbekistan.

Type
Research Article
Copyright
Copyright © The Mineralogical Society of Great Britain and Ireland 2009

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References

Åmark, K., Boren, B. and Westgren, A. (1936) On the crystal structure of Mn5Si3. Svensk Kemisk Tidskrift, 48, 273276.Google Scholar
Aronsson, B. (1960) A note on the composition and crystal structures of MnB2, Mn3Si, Mn5Si3 and FeSi2. Acta Chemica Scandinavica, 14, 14141418.CrossRefGoogle Scholar
Cenzual, K. and Parthé, K.E. (1986) Zr5Ir3 with a deformation superstructure of the Mn5Si3 structure. Acta Crystallographica C, 42, 11011105.CrossRefGoogle Scholar
Djuraev, A.D. and Divaev, F.K. (1999) Melanocratic carbonatites — new type of diamond-bearing rocks, Uzbekistan. Pp. 639—642 in: Mineral Deposits: Processes to Processing(C.J. Stanley, A.H. Rankin, R.J. Bodnar, J. Naden, B.W.D. Yardley, A.J. Criddle, R.D. Hagni, A.P. Gize, J. Pasava, A.J. Fleet, Seltmann, R.,Halls, C., Stemprok, M., B. Williamson, R.J. Herrington, R.E.T. Hill, H.M. Prichard, F. Wall, C.T. Williams, I. McDonald, J.J. Wilkinson, D. Cooke, N.J. Cook, B.J. Marshall, P. Spry, Khin Zaw, L. Meinert, K. Sundblad, P. Scott, S.H.B. Clark, E. Valsami-Jones, N.J. Beukes, H.J. Stein, J.L. Hannah, F. Neubauer, D.J. Blundell, D.H.M. Alderton, M.P. Smith, S. Mulshaw and R.A. Ixer, editors). Balkema. Rotterdam, 1468 pp. 2 vols.Google Scholar
Egorov, K.N., Solov’eva, L.V., Kovach, V.P., Men’shagin, Yu.V., Maslovskaya, M.N., Sekerin, A.P. and Bankovskaya, E.V. (2006) Petrological features of olivine-phlogopite lamproites of the Sayan region: Evidence from Sr-Nd isotope and ICP-MS trace-element data. Geochemistry International, 44, 729—735.CrossRefGoogle Scholar
Errandonea, D., Santamaria-Perez, D., Vegas, A., Nuss, J., Jansen, M., Rodriguez-Hernandez, P. and Munoz, A. (2008) Structural stability of Fe5Si3 and Ni2Si studied by high-pressure X-ray diffraction and ab initio total-energy calculations. Physical Review B, 76, DOI 094113.Google Scholar
Farrugia, L.J. (1999) WinGX suite for small-molecule single-crystal crystallography. Journal of Applied Crystallography, 32, 837—838.CrossRefGoogle Scholar
Jambor, J.L. and Puziewicz, J. (1992) New Mineral Names. American Mineralogist, 77, 1116—1121.Google Scholar
Kraus, W. and Nolze, G. (1996) POWDER CELL —a program for the representation and manipulation of crystal structures and calculation of the resulting X-ray powder diffraction patterns. Journal of Applied Crystallography, 29, 301—303.CrossRefGoogle Scholar
Lutkov, V.S., Mogarovskii, V.V. and Lutkova, V.Ya. (2007) Geochemical anomalies in the mantle of the Pamirs and Tien Shan with applications to the deep-seated sources of ore material. Geochemistry International, 45, 451—464.Google Scholar
Nakamura-Messenger, K., Keller, L.P., Clemett, S.J., Jones, J.H., Palma, R.L., Pepin, R.O., Klock, W., Zolensky, M.E. and Messenger, S. (2008) New manganese silicide mineral phase in an interplanetary dust particle. Lunar and Planetary Science, XXXIX, 2103. http://www.lpi.usra.edu/meetings/ lpsc2008/pdf/2103.pdfGoogle Scholar
Nowotny, H. (1963) Pp. 179—220 in: Electronic Structure and Alloy Chemistry of the Transition Elements(P.A. Beck, editor). John Wiley, New York.Google Scholar
Parthé, E., Jeitschko, W. and Sadagopan, V. (1965) A neutron diffraction study of the Nowotny phase Mo45Si3C 41. Acta Crystallographica, 19, 1031—1037.CrossRefGoogle Scholar
Sheldrick, G.M. (2008) A short history of SHELX. Acta Crystallographica A, 64, 112—122.Google Scholar
Shoemaker, C.B. and Shoemaker, D.P. (1978) Refinement of an R phase Mn85 5Si145. Acta Crystallographica B, 34, 701—705.Google Scholar
Spinat, P., Brouty, C., Whuler, A. and Herpin, P. (1975) Etude structurale de la phase Mn8Si2C. Acta Crystallographica B, 31, 541—547.Google Scholar
Stanley, C.J. and Laflamme, J.H.G. (1998) Preparation of specimens for advanced ore-mineral and environmental studies. Chapter 3, pp. 111—121 in: Modern Approaches to Ore and Environmental Mineralogy(L.J. Cabri and D.J. Vaughan, editors). Mineralogical Association of Canada Short Course Series, 27.Google Scholar
Tatarintsev, V.I., Tsymbal, S.N., Sandomirskaya, S.M., Egorova, L.N., Vashchenko, A.N. and Khnyazkov, A.P. (1990) Iron-bearing manganese silicides from the Priazovye (USSR). Mineralogichesky Zhurnal, 12(6), 35—43 [in Ukrainian].Google Scholar
Woolley, A.R. and Church, A.A. (2005) Extrusive carbonatites: A brief review. Lithos, 85, 1—14.CrossRefGoogle Scholar
Woolley, A.R and Kjarsgaard, B.A. (2008) Carbonatite occurrences of the world: map and database; Geological Survey of Canada, Open File 5796, 2008; 28 pages (1 sheet) http://geopub.nrcan.gc.ca/ moreinfo_e.php?id=225115Google Scholar
Yu, Z. (1984) Two new minerals gupeiite and xifengite in cosmic dusts from Yanshan. Acta Petrologica Mineralogica et Analytica, 3, 231—238.Google Scholar
Yusupov, R G (1993) Geochemical features and accessory-mineral parageneses for orogenic-region diamonds: The Central and Southern Tien Shan. Geochemistry International, 31, 83—92 [English translation, 1994].Google Scholar