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Proshchenkoite-(Y) from Russia — a new mineral species in the vicanite group: descriptive data and crystal structure

Published online by Cambridge University Press:  05 July 2018

G. Raade*
Affiliation:
Department of Geology, Natural History Museum, University of Oslo, P.O. Box 1172, Blindern, NO-0318 Oslo, Norway
J. D. Grice
Affiliation:
Research Division, Canadian Museum of Nature, P.O. Box 3443, Station D, Ottawa Ontario K1P 6P4, Canada
M. Erambert
Affiliation:
Department of Geosciences, University of Oslo, P.O. Box 1047, Blindern, NO-0316 Oslo, Norway
P. Kristiansson
Affiliation:
Department of Nuclear Physics, Lund Institute of Technology, Box 118, SE-221 00 Lund, Sweden
T. Witzke
Affiliation:
Institut für Chemie/Technische Chemie, Universität Rostock, Albert-Einstein-Strasse 3a, DE-18059 Rostock, Germany
*

Abstract

A REE-bearing fluorosilicate from the Tommot REE-Nb deposit in Yakutia, Russia, described without a name in 1966, is characterized here as a new species, proshchenkoite-(Y), of the vicanite group of borosilicates. Wavelength-dispersive electron probe analyses gave the following empirical formula: Y3.70REE7.54Ca1.55Na1.16Mn0.77Th0.10Pb0.0114.83(Fe2+0.83Mn0.15Ti0.021.00Ca1.00(P0.70Si0.26As0.041.00Si0.26B3.20(O34.55F13.4548. Boron was analysed with a nuclear microprobe method based on the nuclear reaction 11B(p,α)2α. The simplified formula is (Y,REE,Ca,Mn)15(Fe2+,Mn)Ca(P,Si)Si6B3O34F14. The mineral is trigonal, R3m, with a = 10.7527(7) Å, c = 27.4002(18) Å, V = 2743.6(6) Å 3, Z = 3. The crystal structure was refined to Rl = 0.042 for 1819 observed reflections. Proshchenkoite-(Y) is isostructural with okanoganite-(Y), vicanite-(Ce) and hundholmenite-(Y), and the differences in site occupancies are discussed. The strongest six reflections of the X-ray powder-diffraction pattern [dobs in Å, (I), (hkl)] are: 4.441, (36), (202); 3.144, (77), (214); 3.028, (45). (009); 2.968, (100), (027); 1.782, (32), (330); and 1.713, (32), (1.2.14). The mineral is optically uniaxial (—) with ω 1.734(2) and 8 1.728(2). The Mohs hardness is about 5; density measured on material subject to incipient metamictization is 4.72 g/cm3, as compared to Dcalc = 4.955 g/cm3.

The result of electron microprobe analyses of alleged okanoganite-(Y) from the type locality in Okanogan County, Washington, USA, is also presented. We find here also that P > Si at one of the sites, whereas the analytical data of Boiocchi et al. (2004) indicate Si > P. Consequently, the mineral we have analysed is the P analogue of okanoganite-(Y), another new species.

Type
Research Article
Copyright
Copyright © The Mineralogical Society of Great Britain and Ireland 2008

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Footnotes

also at: Norwegian Mining Museum, P.O. Box 18, NO-3602 Kongsberg, Norway

References

Ballirano, P., Callegari, A., Caucia, F., Maras, A., Mazzi, F. and Ungaretti, L. (2002) The crystal structure of vicanite-(Ce), a borosilicate showing an unusual (Si3B3O18)15” polyanion. American Mineralogist, 87, 11391143.CrossRefGoogle Scholar
Boggs, R.C. (1980) Okanoganite, a new rare-earth borofluorosilicate from the Golden Horn batholith, Okanogan County, Washington. American Mineralogist, 65, 11381142.Google Scholar
Boiocchi, M., Callegari, A., Ottolini, L. and Maras, A. (2004) The chemistry and crystal structure of okanoganite-(Y) and comparison with vicanite-(Ce). American Mineralogist, 89, 15401545.CrossRefGoogle Scholar
Brese, N.E. and O'Keeffe, M. (1991) Bond-valence parameters for solids. Ada Crystallographica, B47, 192197.Google Scholar
Jarosewich, E. and Boatner, L.A. (1991) Rare-earth element reference samples for electron mieroprobe analysis. Geostandards Newsletter, 15, 397399.CrossRefGoogle Scholar
Mandarino, J.A. (1981) The Gladstone-Dale relationship: Part IV. The compatibility concept and its application. The Canadian Mineralogist, 19, 441450.Google Scholar
Maras, A., Parodi, G.C., Delia Ventura, G. and Ohnenstetter, D. (1995) Vicanite-(Ce): A new Ca-Th-REE borosilicate from the Vico volcanic district (Latium, Italy). European Journal of Mineralogy, 7, 439446.CrossRefGoogle Scholar
McDonough, W.F. and Sun, S.-S. (1995) The composition of the Earth. Chemical Geology, 120, 223253.CrossRefGoogle Scholar
Nekrasov, I.Ya., Gorshkov, A.I., Doynikova, O.A., Nekrasova, R.A., Sivtsov, A.V. and Vlasova, Ye.V. (1992) A new hydrated yttrium-calcium carbonate from the Tommot deposit in NE Yakutia. Doklady Rossiyskiy Akademii Nauk, 326, 833–886 (in Russian). [English translation, 328, 148151 (1994)]Google Scholar
Proshchenko, E.G., Batalieva, N.G. and Bykova, A.V. (1966) A rare-earth fluosilicate from a Siberian pegmatite. Zapiski Vsesoyuznogo Mineralogicheskogo Obshchestva, 95, 339345 (in Russian).Google Scholar
Raade, G., Johnsen, O., Erambert, M. and Petersen, O.V. (2007) Hundholmenite-(Y) from Norway — a new mineral species in the vicanite group: descriptive data and crystal structure. Mineralogical Magazine, 71, 179192.CrossRefGoogle Scholar
Semenov, E.I. (2001) Ores and Minerals of Rare Earths, Thorium and Uranium (Lanthanides and Actinides). GEOS, Moscow, 307 pp. (in Russian).Google Scholar
Sheldrick, G.M. (1990) SHELXTL, a crystallographic computing package, revision 4.1. Siemens Analytical Instruments, Inc., Madison, Wisconsin.Google Scholar
Sheldrick, G.M. (1998) SADABS User Guide. University of Göttingen. Göttingen, Germany.Google Scholar
Skogby, H., Kristiansson, P. and Halenius, U. (2003) An assessment of nuclear mieroprobe analyses of B in silicate minerals. American Mineralogist, 88, 16011604.CrossRefGoogle Scholar
Strunz, H. and Nickel, E.H. (2001) Strunz Mineralogical Tables. Ninth Edition. E. Schweizerbart'sche Verlagsbuchhandlung, Stuttgart, Germany, 870 pp.Google Scholar