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-Nickenich _database_code_amcsd 0001152 10.078 10.078 14.319 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 .69 .030 .030 .033 .015 0 0 FeA 1/3 2/3 .25 .01 .0053 .0053 .0098 .00265 0 0 MgA 1/3 2/3 .25 .99 .0053 .0053 .0098 .00265 0 0 Si1 .24734 .35333 .39204 .85 .0094 .0107 .0080 .0060 .0016 .0017 Al1 .24734 .35333 .39204 .15 .0094 .0107 .0080 .0060 .0016 .0017 Fe2 .5 .5 .25 .08 .0163 .0163 .0091 .0137 0 0 Al2 .5 .5 .25 .92 .0163 .0163 .0091 .0137 0 0 O1 .1237 .4071 0 .027 .022 .0079 .012 0 0 O2 .2176 .2851 .1318 .027 .033 .0245 .0238 -.0001 -.0025 O3 .1410 .4937 .1787 .0153 .0169 .0120 .0102 -.0036 -.0048