gsminmag Mineralogical Magazine Mineralogical Magazine 0026-461X Mineralogical Society 10.1180/minmag.1963.033.262.04 The Kinetics of the Low→High Transformation in Albite I. Amelia Albite under Dry Conditions Mckie Duncan M.A., B.Sc., Ph.D., A.R.I.C., F.G.S. McConnell J. D. C. M.Sc., M.A., Ph.D. Department of Mineralogy and Petrology, Downing Place, Cambridge 9 1963 33 262 581 588 Copyright © 1963, The Mineralogical Society 1963 Summary

The transformation was followed in Amelia albite powders by variation in 2θ131−2θ13¯1 with time under isothermal conditions at various temperatures in the range 920°–1080°C. The activation energy of about 74 kcal mole-1 is rather larger than that obtained for the ordering process in synthetic NaAlSi3O8 under hydrothermal conditions.