Hostname: page-component-586b7cd67f-gb8f7 Total loading time: 0 Render date: 2024-12-01T01:11:32.048Z Has data issue: false hasContentIssue false

The lattice distortion and possible causes of the lazurite incommensurate and commensurate modulation structure

Published online by Cambridge University Press:  10 January 2013

A. N. Sapozhnikov
Affiliation:
Institute of Geochemistry, Russian Academy of Sciences, Siberian Department, Irkutsk, 664033, Russia
E. K. Vasil'ev
Affiliation:
Institute of the Earth's Crust, Russian Academy of Sciences, Siberian Department, Irkutsk, 664033, Russia

Abstract

By methods of X-ray structure analysis commensurate (one dimensional) and incommensurate (three-dimensional) modulations of the lazurite structure from Baikal deposits are considered. The analysis of the X-ray diffraction powder and single crystal data showed that the one-dimensional (anisotropic) modulation deforms the lazurite cubic structure and is manifested in a broadening and splitting of sublattice lines on the powder diffraction pattern of the mineral. At a three-dimensional modulation, the cubic structure is maintained. It is concluded that a density modulation is a cause of the incommensurate modulation of the lazurite structure. Due to this arrangement, a crystallographic equivalency of subcells is maintained. The cause of the commensurate modulation is an ordered distribution of intraframework units and the displacement modulation where all atoms of the mineral structure participate.

Type
Research Article
Copyright
Copyright © Cambridge University Press 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

Guinier, A. (1956). Theorie et Technique de la Radiocrystallographie (Dunod, Paris).Google Scholar
Ivanov, V. G., and Sapozhnikov, A. N. (1985). Lazurites of USSR (in Russian) (Nauka, Novosibirsk), p. 172.Google ScholarPubMed
Lipson, H., and Steepl, H. (1970). Interpretation of X-ray Powder Diffraction Patterns (MacMillan, New York).Google Scholar
Putnis, A., and McConnell, J. D. C. (1980). Principles of Mineral Behavior (Blackwell Scientific, Oxford, London).Google Scholar
Sapozhnikov, A. N. (1990). Zap. Vses. Mineral. Obshch. 119(1), 110116 (in Russian).Google Scholar
Sapozhnikov, A. N., Ivanov, V. G., and Kashaev, A. A. (1979). Crystal Chemistry and Structural Mineralogy (in Russian) (Nauka, Leningrad), pp. 4854.Google Scholar
Sapozhnikov, A. N., Vasil'ev, E. K., and Bayliss, P. (1992). Powder Diffr. 7, 134136.CrossRefGoogle Scholar
Smith, J. V. (1974). Feldspar Minerals. Crystal Structure and Physical Properties (Springer-Verlag, Berlin), Vol. 1.Google Scholar
Wilson, A. G. C. (1949). X-ray Optics (Methuen, London), p. 127.Google Scholar