AM_Siderophyllite_4 Formula: Al2.54 Si2.28 Fe2.38 K O12 H2 Name: Siderophyllite Unit cell: 5.3649 9.2892 10.2698 90.0 100.242 90.0 , V=503.65 Space group: C12/M1 (12)

Redhammer G J , Roth G , American Mineralogist , 87 (2002) p.1464-1476, Single-crystal structure refinements and crystal chemistry of, synthetic trioctahedral micas KM3(Al,Si)4O10(OH)2, where, M = Ni, Mg, Co, Fe, Al, Sample: Sd87#4