Location of Argon and Water in Cordierite

J. V. Smith and W. Schreyer
Department of Geophysical Sciences, University of Chicago, Chicago 37, Illinois, U.S.A.
Geophysical Laboratory, Carnegie Institution of Washington, Washington 8, D.C., U.S.A.

Summary: Evaluation of X-ray powder diffraction data shows that argon atoms (radius 1·9 Å) lie at the centres of the large holes in the cordierite structure. The reflection intensities for hydrous cordierite differ from those for anhydrous cordierite but to a lesser degree than those for argon-bearing cordierite. Although analysis is uncertain, it appears that the smaller water molecules (radius 1·4 Å) do not occupy either the centres of the six-membered rings or the centres of the large cavities. It is possible that they may be attached to the walls of the large cavities or occur partly as hydroxyl groups in the framework. Single-crystal X-ray analysis is necessary to resolve this problem.

Mineralogical Magazine; September 1962 v. 33; no. 258; p. 226-236; DOI: 10.1180/minmag.1962.033.258.05
© 1962, The Mineralogical Society
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