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An experimental study of ordering in sodium-rich alkali feldspars

Published online by Cambridge University Press:  14 March 2018

Ian Parsons
Ian Parsons*
Affiliation:
Department of Geology and Mineralogy, Marischal College, Aberdeen
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Summary

Variations in the value of 2θ131 – 2θ13̄1 of two anorthoclase feldspars of compositions Ab95Or5 and Ab90Or10 were investigated by hydrothermal crystallization of gels for long periods in the temperature range 500–950 °C, at water vapour pressures up to 15 000 lb/in.2. The results are compared to those obtained by MacKenzie (1957) for pure albite. It is shown that the variation in 2θ131 – 2θ13̄1 is largely the result of Al-Si order-disorder and that at 700 °C and above the magnitude of the variation in the anorthoclases suggests that the degree of order is like that in albite, but at lower temperatures, particularly below 600 °C, the variation is less, and the anorthoclases are less ordered than albite at the same temperatures. At 600 °C and above the rate of attainment of equilibrium is the same for all three compositions. Below 600 °C Ab95Or5 behaves differently to albite. At low temperatures the equilibrium degree of Al-Si order in mixed Na-K feldspars is a function of composition as well as of temperature of crystallization.

Type
Research Article
Information
Mineralogical magazine and journal of the Mineralogical Society , Volume 36 , Issue 284 , December 1968 , pp. 1061 - 1077
Copyright
Copyright © The Mineralogical Society of Great Britain and Ireland 1968

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References

Chayes, (F.) and MacKenzie, (W. S.), 1957. Amer. Min., vol. 42, p. 534.Google Scholar
Czamanske, (G. K.), 1965. Journ. Geol., Chicago, vol. 73, 10. 293.Google Scholar
Donnay, (G.) and Donnay, (J. D. H.), 1952. Amer. Journ. Sci., Bowen vol., p. 115.Google Scholar
Eberhard, (E.), 1967. Schweiz. Min. Petr. Mitt., vol. 47, 10. 385.Google Scholar
Grundy, (H. D.), Brown, (W. L.), and MacKenzie, (W. S.), 1967. Min. Mag. vol. 36, p. 83.Google Scholar
Hamilton, (D. L.) and MacKenzie, (W. S.), 1960. Journ. Petrology, vol. 1, p. 56.Google Scholar
Laves, (F.), 1960. Zeits. Krist., vol. 113, p. 265.Google Scholar
Luth, (W. C.) and Tuttle, (O. F.), 1966. Amer. Min., vol. 51, p. 1359.Google Scholar
MacKenzie, (W. S.), 1952. Amer. Journ. Sci., Bowen vol., p. 319.Google Scholar
MacKenzie, (W. S.), 1957. Ibid., vol. 255, p. 481.CrossRefGoogle Scholar
MacKenzie, (W. S.) and Smith, (J. V.), 1961. Inst. Lucas Mallada, C.S.I.C. Madrid. Cursillos y Conferencias, vol. 8, p. 53.Google Scholar
MacKenzie, (W. S.) and Smith, (J. V.), 1962. Norsk Geol. Tidsskr., vol. 42, part 2, p. 72.Google Scholar
Orville, (P. M.), 1963. Amer. Journ. Sci., vol. 261, p. 201.Google Scholar
Orville, (P. M.), 1967. Amer. Min., vol. 52, p. 55.Google Scholar
Parsons, (I.), 1965. Journ. Petrology, vol. 6, p. 365.CrossRefGoogle Scholar
Roy, (R.), 1956. Journ. Amer. Ceram. Soc., vol. 39, p. 145.Google Scholar
Smith, (J. V.) and Mackenzie, (W. S.), 1958. Amer. Min., vol. 43, p. 872.Google Scholar
Smith, (J. V.) and Mackenzie, (W. S.), 1961. Inst. Lucas Mallada, C.S.I.C. Madrid. Cursillos y Couferencias, vol. 8, p. 39.Google Scholar
Tuttle, (O. F.) and Bowen, (N. L.), 1958. Geol. Soc. Amer. Mem. 74.Google Scholar
Wright, (T. L.) and Stewart, (D. B.), 1968. Amer. Min., vol. 53, p. 38.Google Scholar