Cronstedtite
Hendricks S B
American Mineralogist 24 (1939) 529-539
Random structures of layer minerals as illustrated by cronstedtite
(2FeO.Fe2O3.SiO2.2H2O). Possible iron content of kaolin
_database_code_amcsd 0000022
3.16 3.16 21.25 90 90 120 R3
atom  x y   z  occ
Si    0 0 .03   .5
Fe    0 0 .03   .5
Fe    0 0 .83 .900
O1    0 0 .11 .333
OH1   0 0 .11 .667
OH2   0 0 .54
O2   .5 0   0 .667