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: Norway _database_code_amcsd 0001150 10.104 10.104 14.306 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 .90 .029 .029 .031 .0145 0 0 FeA 1/3 2/3 .25 .16 .007 .007 .009 .0035 0 0 MgA 1/3 2/3 .25 .84 .007 .007 .009 .0035 0 0 Si1 .2501 .3554 .3921 .86 .0084 .0100 .0058 .0046 .0010 .0010 Al1 .2501 .3554 .3921 .14 .0084 .0100 .0058 .0046 .0010 .0010 Fe2 .5 .5 .25 .03 .0091 .0091 .0068 .0072 0 0 Al2 .5 .5 .25 .97 .0091 .0091 .0068 .0072 0 0 O1 .1238 .4090 0 .025 .017 .009 .004 0 0 O2 .2196 .2911 .1327 .029 .043 .021 .030 -.005 -.004 O3 .1383 .4936 .1789 .016 .016 .012 .010 -.003 -.005