Pyrophyllite Wardle R, Brindley G W American Mineralogist 57 (1972) 732-750 The crystal structures of pyrophyllite, 1Tc, and of its dehydroxylate Note: this is polytype pyrophyllite-1Tc _database_code_amcsd 0000286 5.1919 9.1224 9.4990 91.17 100.21 88.62 C-1 atom x y z Al .552 .149 0 Si1 .225 .486 .286 Si2 .749 .312 .286 O1 .25 .25 0 O2 .123 .492 .115 O3 .728 .292 .115 O4 .037 .378 .355 O5 .717 .152 .355 O6 .522 .425 .320