Biotite Ohta T, Takeda H, Takeuchi Y American Mineralogist 67 (1982) 298-310 Mica polytypism: Similarities in the crystal structures of coexisting 1M and 2M(1) oxybiotite _database_code_amcsd 0000861 5.3204 9.210 10.104 90 100.102 90 C2/m atom x y z occ B(1,1) B(2,2) B(3,3) B(1,2) B(1,3) B(2,3) Mg1 0 0 .5 .624 .0040 .0012 .0033 0 .0012 0 Fe1 0 0 .5 .190 .0040 .0012 .0033 0 .0012 0 Al1 0 0 .5 .186 .0040 .0012 .0033 0 .0012 0 Mg2 0 .34538 .5 .507 .0033 .00286 .00308 0 .00073 0 Fe2 0 .34538 .5 .289 .0033 .00286 .00308 0 .00073 0 Ti2 0 .34538 .5 .168 .0033 .00286 .00308 0 .00073 0 Al2 0 .34538 .5 .036 .0033 .00286 .00308 0 .00073 0 Si .0730 .16733 .22283 .71 .0045 .00158 .00313 .00004 .00087 .00001 Al .0730 .16733 .22283 .266 .0045 .00158 .00313 .00004 .00087 .00001 Fe .0730 .16733 .22283 .024 .0045 .00158 .00313 .00004 .00087 .00001 K 0 .5 0 .0167 .0053 .0075 0 .0023 0 O1 .0177 0 .1666 .0146 .0026 .0041 0 .0006 0 O2 .3217 .2315 .1645 .0098 .0044 .0040 -.0019 .0017 -.0005 O3 .1298 .1697 .3905 .0049 .0015 .0031 .0001 .0011 -.0001 O4 .1335 .5 .4006 .0057 .0022 .0030 0 .0010 0