Phlogopite
Hendricks S B, Jefferson M E
American Mineralogist 24 (1939) 729-771
Polymorphism of the micas with optical measurements
Note: data is reproduced from Jackson and West (1930)
_database_code_amcsd 0000025
5.32 9.21 20.08 90 95 90 C2/c
atom     x     y    z occ
K        0  .083  .25
Mg1    .25  .083    0
Mg2    .75   .25    0
Si1  -.033 -.250 .135 .75
Si2  -.033  .417 .135 .75
Al1  -.033 -.250 .135 .25
Al2  -.033  .417 .135 .25
O1    .228  .333 .164
O2    .228 -.167 .164
O3    .480  .083 .164
O4   -.062 -.167 .055
O5   -.062  .417 .055
OH   -.062  .083 .058 .50
F    -.062  .083 .058 .50