Osumilite Brown G E, Gibbs G V American Mineralogist 54 (1969) 101-116 Refinement of the crystal structure of osumilite _database_code_amcsd 0000188 10.155 10.155 14.284 90 90 120 P6/mcc atom x y z occ Biso K 0 0 .25 .71 3.6 Na 0 0 .25 .28 3.6 Ca 0 0 .25 .01 3.6 Mg .3333 .6667 .25 .46 .90 Fe .3333 .6667 .25 .46 .90 Mn .3333 .6667 .25 .08 .90 Si1 .1037 .3513 .1085 .85 1.25 Al1 .1037 .3513 .1085 .15 1.25 Al2 .5 0 .25 .88 1.31 Fe2 .5 0 .25 .12 1.31 O1 .1216 .4046 0 2.5 O2 .2142 .2837 .1316 2.4 O3 .1372 .4913 .1789 1.8 Wat .031 .114 0 .166 9