The Pressure Dependence of the Dehydration of Gypsum to Bassanite

J. D. C. McConnell, D. M. Astill and P. L. Hall
Schlumberger Cambridge Research, P.O. Box 153, Cambridge, CB3 0HG, U.K.

Abstract: A new experimental determination of the stability relationships for the dehydration of gypsum to the hemihydrate mineral bassanite at elevated temperature and pressure is described. The experimental method used depends on the observation of very small changes in pressure on the onset of reaction due to the potential volume change in the reaction. The technique yields P-T data of very high precision for this dehydration reaction, and the method is likely to be of use for other reactions. The experimental P-T results have been compared with those calculated from existing thermodynamic data for this reaction.

Keywords: gypsum • bassanite • dehydration

Mineralogical Magazine; September 1987 v. 51; no. 361; p. 453-457; DOI: 10.1180/minmag.1987.051.361.12
© 1987, The Mineralogical Society
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