gsminmag Mineralogical Magazine Mineralogical Magazine 0026-461X Mineralogical Society 10.1180/minmag.1953.030.221.06 A Hydrous Mica from Yorkshire Fireclay Carr K. B.Sc. Grimshaw R. W. B.Sc., Ph.D., A.R.I.C. Roberts A. L. Ph.D., F.R.I.C. Fuel Department, University of Leeds 6 1953 30 221 139 144 Copyright © 1953, The Mineralogical Society 1953