Re-investigation of Clino-Ferrosilite from Lake Naivasha, Kenya

M. G. Bown
Department of Mineralogy and Petrology, Cambridge

Summary: The clino-ferrosilite from the lithophysae in an obsidian flom Lake Naivasha, Kenya, originally examined by Bowen (1935), has been shown to be substantially pure FeSiO2, with about 5% MnSiO2 in solid solution. It has the same space-group, P21/c, as clino-enstatite and pigeonite. The unit-cell dimensions are a = 9.718 Å, b = 9·088 Å, c = 5·239 Å, β = 108° 27′. These do not conform to the scheme proposed by Brown (1960): reasons are given why this was not unexpected.

Mineralogical Magazine; 1965 v. 34; no. 268; p. 66-70; DOI: 10.1180/minmag.1965.034.268.05
© 1965, The Mineralogical Society
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