AM_Osumilite_8 Formula: K.75 Fe Mg1.18 Si10.32 Al4.5 O30 Name: Osumilite Unit cell: 10.127 10.127 14.288 90.0 90.0 120.0 , V=1269.01 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, Sample: Sardinia