gsminmag Mineralogical Magazine Mineralogical Magazine 0026-461X Mineralogical Society 10.1180/minmag.1976.040.314.08 Crystallinity Among Some Hydrous Aluminium Phosphates McConnell Duncan The Ohio State University, Columbus, Ohio 43210 6 1976 40 314 609 610 19 5 1975 26 7 1975 Copyright © 1976, The Mineralogical Society 1976 Summary

Compositions of nine hydrous aluminium phosphates are considered with respect to the Al, P, and H contents per 8 oxygens, and it is suggested that when the ratio (Al. P)/H is less than 0·11 (or (Al.P2)/H2 is less than 0·01 such compositions do not crystallize. Examples are bolivarite and evansite.