Osumilite Armbruster T, Oberhansli R American Mineralogist 73 (1988) 585-594 Crystal chemistry of double-ring silicates: Structural, chemical, and optical variation in osumilites Sample: Eifel-B93 _database_code_amcsd 0001151 10.071 10.071 14.303 90 90 120 P6/mcc atom x y z occ U(1,1) U(2,2) U(3,3) U(1,2) U(1,3) U(2,3) KC 0 0 .25 .48 .029 .029 .028 .0145 0 0 FeA 1/3 2/3 .25 .67 .0068 .0068 .0105 .0034 0 0 MgA 1/3 2/3 .25 .33 .0068 .0068 .0105 .0034 0 0 Si1 .2466 .3538 .39217 .85 .0113 .0137 .0100 .0063 .0018 .0006 Al1 .2466 .3538 .39217 .15 .0113 .0137 .0100 .0063 .0018 .0006 Fe2 .5 .5 .25 .08 .029 .029 .0177 .026 0 0 Al2 .5 .5 .25 .92 .029 .029 .0177 .026 0 0 O1 .1252 .4085 0 .026 .024 .010 .010 0 0 O2 .2208 .2878 .1323 .032 .036 .029 .027 .006 .001 O3 .1416 .4949 .1790 .022 .023 .0140 .015 -.002 -.002