AM_Osumilite_7 Formula: K.76 Fe1.37 Mg.84 Si10.32 Al4.47 O30 Name: Osumilite Unit cell: 10.15 10.15 14.286 90.0 90.0 120.0 , V=1274.60 Space group: P6/MCC (192)

Armbruster T , Oberhansli R , American Mineralogist , 73 (1988) p.585-594, Crystal chemistry of double-ring silicates: Structural, chemical, and optical, variation in osumilites, Japan-Hayasaki