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 Sample: in the 2M1 setting _database_code_amcsd 0000862 5.3175 9.212 19.976 90 95.09 90 C2/c atom x y z occ B(1,1) B(2,2) B(3,3) B(1,2) B(1,3) B(2,3) Mg1 .75 .25 0 .612 .0051 .0015 .00071 0 .00014 0 Fe1 .75 .25 0 .200 .0051 .0015 .00071 0 .00014 0 Al1 .75 .25 0 .188 .0051 .0015 .00071 0 .00014 0 Mg2 .2321 .07750 -.00001 .513 .0077 .00186 .00068 .0016 0 .00009 Fe2 .2321 .07750 -.00001 .296 .0077 .00186 .00068 .0016 0 .00009 Ti2 .2321 .07750 -.00001 .168 .0077 .00186 .00068 .0016 0 .00009 Al2 .2321 .07750 -.00001 .023 .0077 .00186 .00068 .0016 0 .00009 Si1 .4624 .24902 .13850 .712 .0046 .0015 .00065 .0003 .00007 0 Al1 .4624 .24902 .13850 .280 .0046 .0015 .00065 .0003 .00007 0 Fe1 .4624 .24902 .13850 .008 .0046 .0015 .00065 .0003 .00007 0 Si2 .9645 .4163 .13857 .708 .0049 .0017 .00063 .0003 .00003 .00004 Al2 .9645 .4163 .13857 .264 .0049 .0017 .00063 .0003 .00003 .00004 Fe2 .9645 .4163 .13857 .028 .0049 .0017 .00063 .0003 .00003 .00004 K 0 .0832 .25 .0164 .0056 .00178 0 .00043 0 O11 .7421 .3139 .1664 .0102 .0047 .00089 -.0016 .0001 .00015 O21 .2416 .3512 .1677 .0103 .0045 .00088 .0024 -.0001 -.00032 O22 .4352 .0822 .1675 .0163 .0028 .00085 -.0001 .0008 0 O31 .4309 .2477 .05473 .0054 .0017 .00064 .0011 .0001 -.0001 O32 .9392 .4172 .05466 .0053 .0018 .00060 .0014 0 -.0001 O4 .9333 .0827 .04994 .0071 .0023 .00066 .0020 0 -.0003