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Nepheline solid solutions

Published online by Cambridge University Press:  14 March 2018

Gabrielle Donnay ,
J. F. Schairer  and
J. D. H. Donnay
Gabrielle Donnay
Affiliation:
Geophysical Laboratory, Carnegie Institution of Washington, Washington, D.C., U.S.A.
J. F. Schairer
Affiliation:
Geophysical Laboratory, Carnegie Institution of Washington, Washington, D.C., U.S.A.
J. D. H. Donnay
Affiliation:
The Johns Hopkins University, Baltimore, Maryland, U.S.A.
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Summary

Published chemical analyses demonstrate that the nepheline formula should be written KxNayCaz□s-(x+y+z)Alx+y+2zSi16-(x+y+2z)O32, where □ stands for vacant sites. X-ray data are presented for the nepheline phase in four binary systems: Ne-CaAl2O4, Ne-An, Ne-Ab, Ne-Kp. Only in two of these systems do the cell-dimensions change with composition. In the first one, the cell-volume V increases linearly with increasing calcium content; in the last one, two singularities in the curve of V against x divide the phase Na8-xKxAl8Si8O32 into three subphases: subpotassic (0 < x < 0·25), mediopotassic (0·25 < x < 2·00), and perpotassic (2·00 < x < 4·73). Only in the subpotassic range are both high- and low-temperature forms found. Twenty-eight natural nephelines, for which chemical analyses and X-ray data are available in the literature, show that only the potassium content affects cell-dimensions. Although all analysed natural nephelines fall outside the subpotassic range, the re-examination of a Monte Somma specimen studied by Bannister (1931) reveals a few euhedral crystals of subpotassic nepheline in a mediopotassic phase.

Type
Research Article
Information
Mineralogical magazine and journal of the Mineralogical Society , Volume 32 , Issue 245 , June 1959 , pp. 93 - 109
Copyright
Copyright © The Mineralogical Society of Great Britain and Ireland 1959

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References

Bannister, (F. A.), 1931. Min. Mag., vol. 22, p. 569.Google Scholar
Bowen, (N. L.), 1912. The binary system: Na2A12Si2O8-CaAl2Si2O8. Abstract of Thesis, Mass. Inst. of Tech., pp. 1-14.Google Scholar
Bowen, (N. L.) 1917. Amer Journ. Sci., set. 4, vol. 43, p. 115 [M.A. 1-167].Google Scholar
Buergeh, (M. J.), (G. E.), Klein, and (G.), Donnay, 1954. Amer. Min., vol. 39, p. 805 [M.A. t2-528].Google Scholar
Cesáro, (G.), 1920. Mém. Aead. roy. Belgique (Cl. Se.) Coll. in-8° Ser. 2, vol. 4, p. 1.Google Scholar
Donnay, (G.), 1957. Third International Meeting on Reactivity of Solids, Madrid, April 1956, Section I, p. 279.Google Scholar
Goldsmith, (J. R.), 1949. Amer. Min., vol. 34, p. 471 [M.A. 11-94].Google Scholar
Greig, (J. W.) and BARTH, (T. F. W.), 1938. Amer. Journ. Sci., ser. 5, vol. 35 A, p. 93 [M.A. 7-287].Google Scholar
Gummer, (W. K.), 1943. Journ. Geol., Chicago, vol. 51, p. 503 [31.A. 9-285].Google Scholar
Hahn, (Th.) and Buerger, (M. J.), 1955. Zeits. Krist., vol. 106, p. 308.Google Scholar
MacKenzie, (W. S.), 1957. Amer. Journ. Sci., vol. 225, p. 481.Google Scholar
Miyashiro, (A.) and Miyashiro, (T.), 1954. Journ. Fae. Sci. Univ. Tokyo, Sect. II, vol. 9, p. 267 [31.A. 12 528].Google Scholar
Smith, (J. V.) and Sahama, (Th. G.), 1954. Min. Mag., vol. 30, p. 439 [M.A. 12 506].Google Scholar
Smith, (J. V.) and Tuttle, (O. F.), 1957. Amer. Journ. Sci., vol. 255, p. 282.CrossRefGoogle Scholar