Determination of the Composition of Kalsilites by an X-ray Method

Th. G. Sahama, K. J. Neuvonen and Kai Hytönen
Professor of Geochemistry, Institute of Geology, Helsinki, Finland
Geological Survey, Helsinki, Finland
Institute of Geology, Helsinki, Finland

Summary: Three new analyses of kalsilite are given, with optical and X-ray data; two (K/(K + Na) = 0·95. 0·98) are from rocks where it is closely associated with nepheline. An analysis of one of the nephelines is also given (K/(K + Na) = 0·31). The cell dimensions vary appreciably with sodium content, and the composition of kalsilite may be determined from the equation: 100 K/(K + Na) = 100−227·27(Δ 6·264), where Δ is the difference, in degrees, between the diffraction angles 2ϑ for 101¯2 and 101¯1, using Cu-Kα radiation.

Mineralogical Magazine; September 1956 v. 31; no. 234; p. 200-208; DOI: 10.1180/minmag.1956.031.234.02
© 1956, The Mineralogical Society
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