Hostname: page-component-76fb5796d-qxdb6 Total loading time: 0 Render date: 2024-04-27T12:06:52.672Z Has data issue: false hasContentIssue false
  • English
  • Français

Rotated and extended model structures in amphiboles and pyroxenes

Published online by Cambridge University Press:  05 July 2018

A. D. Law  and
E. J. W. Whittaker
A. D. Law
Affiliation:
Department of Geology and Mineralogy, Parks Road, Oxford OXI 3PR
E. J. W. Whittaker
Affiliation:
Department of Geology and Mineralogy, Parks Road, Oxford OXI 3PR
Get access Rights & Permissions [Opens in a new window]

Summary

The model for the amphibole and pyroxene structures based on close-packed oxygen layers introduced by Thompson is investigated systematically. It is shown that different features of it can best be understood in terms of three different symbolisms: the O and S rotations of tetrahedra; the A,B, C stacking notation for close-packed layers; and the c, h notation for the relationship of close-packed layers to their neighbours. The possible stacking arrangements and their space-groups are derived systematically. Relationships between the close-packed, fully rotated, model and the extended chain model are discussed, and some important drawbacks in the former model are pointed out, especially in connection with real amphibole structures.

Type
Research Article
Information
Mineralogical Magazine , Volume 43 , Issue 329 , March 1980 , pp. 565 - 574
Copyright
Copyright © The Mineralogical Society of Great Britain and Ireland 1980

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.)

Footnotes

*

Present address: Queen Mary College, London.

References

Hawthorne, (F. C), 1979. The crystal chemistry of the amphiboles. X. Refinement of the crystal structure of ferro-glaucophane and an ideal polyhedral model for clinoamphiboles. Can. Mineral. 17, 1-10.Google Scholar
Papike, (J. J.) and Ross, (M.), 1970. Gedrites; crystal structures and intracrystalline cation distributions. Am. Mineral. 55, 1945-72. [M.A. 71-1754]Google Scholar
Papike, (J. J.) Prewitt, (C. T.), Sueno, (S.), and Cameron, (M.), 1973. Pyroxenes: comparisons of real and ideal structural topologies. Z. Kristallogr. 138, 254-73. [M.A. 74-902]CrossRefGoogle Scholar
Smyth, (J. R.), 1971. Proto-enstatite: a crystal structure refinement at 1100°C. Ibid. 134, 262-74. [M.A. 72-2753]Google Scholar
Thompson, (J.B.Jr.), 1970. Geometrical possibilities for amphibole structures: model biopyriboles. Am. Mineral. 55, 292-3 (abstract).Google Scholar
Warren, (B. E.), 1929. The structure of tremolite. Z. Kristallogr. 72, 42-57. [M.A. 4-201]Google Scholar
Warren, (B. E.) and Bragg, (W. L.), 1928. The structure of diopside CaMg(SiO3)2. Ibid. 69, 168-93. [M.A. 4-31]Google Scholar
Warren, (B. E.) and Modell, (D. I.) 1930. The structure of antho-phyllite H2Mg7(SiO3)8. Ibid. 75, 168-78. [M.A. 4-463]Google Scholar
Wells, (A. F.), 1962. Structural Inorganic Chemistry, 3rd edn., pp. H2ff. Oxford University Press.Google Scholar
Whittaker, (E. J. W.), 1949. The structure of Bolivian crocidolite. Ada Crystallogr. 2, 312-17. [M.A. 11-101]CrossRefGoogle Scholar