Hostname: page-component-cd9895bd7-gbm5v Total loading time: 0 Render date: 2024-12-18T14:26:50.905Z Has data issue: false hasContentIssue false

Crystal structure of KBSi3O8 isostructural with danburite

Published online by Cambridge University Press:  05 July 2018

Mitsuyoshi Kimata*
Affiliation:
Institute of Geoscience, University of Tsukuba, Ibaraki 305, Japan

Abstract

The crystal structure of KBSi3O8 (orthorhombic, Pnam, with a = 8.683(1), b = 9.253(1), c = 8.272(1) Å,, V = 664.4(1) Å3, Z = 4) has been determined by the direct method applied to 3- dimensional rcflection data. The structure of a microcrystal with the dimensions 20 × 29 × 37 μm was refined to an unweightcd residual of R = 0.031 using 386 non-zero structure amplitudes. KBSi3O8 adopts a structure essentially different from recdmergneritc NaBSi3O8, with the low albite (NaAlSi3O8) structure, and isotypic with danburite CaB2Si2Os which has the same topology as paracelsian BaAl2Si2O8. The chenfical relationship between this sample and danburitc gives insight into a new coupled substitution; K+ + Si4+ = Ca2+ + B3+ in the extraframework and tetrahedral sites. The present occupancy refinement revealed partial disordering of B and Si atoms which jointly reside in two kinds of general equivalent points, T(1) and T(2) sites. Thus the expanded crystal-chemical formula can be written in the form K(B0.44Si0.56)2(B0.06Si0.94)2O8

The systematic trend among crystalline compounds with the M+T3+T4+3O8 formula suggests that they exist in one of four structural types; the feldspar structures with T3+/T4+ ordered and/or disordered forms, and the paracelsian and the hollandite structures.

Type
Crystal Structures
Copyright
Copyright © The Mineralogical Society of Great Britain and Ireland 1993

Access options

Get access to the full version of this content by using one of the access options below. (Log in options will check for institutional or personal access. Content may require purchase if you do not have access.)

References

Appleman, D. E. and Clark, J. R. (1965) Amer. Mine ral., 50, 1827–50.Google Scholar
Brown, I. D. (1981) In Structure and Bonding in CJ3,stal.v, 2. (M. O'Kccffc and A. Navrotsky, cds.). Academic Press, New York, 130.Google Scholar
Dusmatov, V. O., Popova, N. A., and Kabanova, L. K. (1967) l)okl. Akad. Nauk Tadhzik S.S.R., 10, 513.Google Scholar
Eugster, P. H. and Mclver, N. L. (1959) Geol. Soc. Arner. Bull., 70, 1598–9.Google Scholar
Farmer, V. C. (1972) The Infrared Spectra of Minerals. Min. Soc., London.Google Scholar
Finger, L. W. (1969) Carnegie Inst. Year Book, 67, 216–7.Google Scholar
Ghose, S., Wan, C., and Ulbrieh, H. H. (1976) Acta Cry st., B32, 842-32.Google Scholar
Grew, E. S., Pertsev, N. N., Boronikhin, V. A., Borisovskiy, S. Y., Yates, M. G., and Marquez, N. (1991) Amer. Mineral., 76, 1061–80.Google Scholar
Henderson, P. (1986) In Rare Earth Element Geochemistry (P. Henderson, ed.). Elsevier, Amsterdam, 132.Google Scholar
Khomyankov, A. P., Semenov, I. E., Kazakova, M. E., and Sbumyatskaya, N. G. (1979) Zap. Vses. Min. Obsheh., 108, 5659.(in Russian).Google Scholar
Kimata, M. (1977) J. Min. Petr. Econ. Geol., 72, 162–72.Google Scholar
Kimata, M. (1988) Mineral. Mag. 52, 257–65.Google Scholar
Liebau, F. (1985) Structural Chemistry of Silicates. Springer-Verlag, Berlin.Google Scholar
Lima-de-Faria, J., Hellner, E., Ibebau, F., Makovicky, E., and Parthe, E. (1990) Acta Crvst., A46, 1-11.Google Scholar
Lindbloom, J. T., Gibbs, G. V., and Ribbe, P. H. (1974) Amer. Mineral., 59, 1267–71.Google Scholar
Mandarino, J. (1981) Can. Mineral., 19, 441650.Google Scholar
Marlin, R. F. (1971) Amer. Mineral., 56, 282–91.Google Scholar
Mason, R. A. (1980) Contrib. Mineral. Petrol., 72, 329–33.Google Scholar
Milton, C., Axelrod, J. M., and Grimaldi, F. S. (1960) Geol. Soc. Am. Bull., 6S, 1286-7.Google Scholar
Nakamoto, K. (1986) bzfrared and Raman Spectra of Inorganic and Coordination Compounds. 4th Ed., Wiley-Interscience, New York.Google Scholar
Phillips, M. W., Gibbs, G. V., and Ribbe, P. H. (1974) Amer. Mineral., 59, 7985.Google Scholar
Povarennykh, A. S. (1972) Crystal Chemical Classification of Minerals, Vol. 1 and 2 (translated from Russian by Bradley, J. E. S.), Plenum Press, New York.Google Scholar
Smith, J. V. and Brown, W. I. (1988) In Feldspar Minerals. Vol. 1, Crystal structures, physical, chemical, and microtextural properties. Springer-Verlag, Berlin.Google Scholar
Wells, A. F. (1984) Structural Inorganic Chemistry, 5th ed., Clarendon Press, Oxford.Google Scholar