gsminmag Mineralogical Magazine Mineralogical Magazine 0026-461X Mineralogical Society 10.1180/minmag.1969.037.286.14 On the Oriented Transformation of Ca(OH)2 to CaO Datta N. Chatterji S. Jeffery J. W. Mackay A. L. Birkbeck College, Department of Crystallography, University of London 6 1969 37 286 250 252 27 9 1968 28 11 1968 Copyright © 1969, The Mineralogical Society 1969 Summary

The conversion of Ca(OH)2 to CaO has been studied by X-ray diffraction techniques. When Ca(OH)2 crystals are heated in vacuo the conversion is oriented, but not when they are heated at atmospheric pressure. This difference is attributed to the lowering of the decomposition temperature in vacuo and consequent lower thermal vibration.