gsminmag Mineralogical Magazine Mineralogical Magazine 0026-461X Mineralogical Society 10.1180/minmag.1967.036.279.04 The Hydroxyl-Stretching Region of the Biotite Mica Spectrum1 Wilkins R. W. T. M.Sc., Ph.D. Department of Geological Sciences, Harvard Universityl Cambridge, Massachusetts

Published under the auspices of the Committee on Experimental Geology and Geophysics at Harvard University.

 9 1967 36 279 325 333 6 2 1967 Copyright © 1967, The Mineralogical Society 1967 Summary

An interpretation of part of the hydroxyl-stretching region of the infra-red absorption spectrum of biotite is proposed. A consideration of band shapes enables the interpretation to be quantified and tested against a series of natural biotites. The equation derived may be used to determine the atomic ratio Mg2+/(Mg2++Fe2+) in biotites but the necessary assumptions and simplifications make it unlikely that the method will be very useful in practice.