gsminmag Mineralogical Magazine Mineralogical Magazine 0026-461X Mineralogical Society 10.1180/minmag.1939.025.165.03 An X-Ray Examination of Some Potash-Soda-Felspars Chao S. H. D. L. Smare Taylor W. H. Physics Department, College of Technology, Manchester 6 1939 25 165 338 350 Copyright © 1939, The Mineralogical Society 1939