Hollandite_4 Formula: K (Si3 Al) O8 Name: Hollandite Unit cell: 9.237 9.237 2.706 90.0 90.0 90.0 , V=230.88 Space group: I14/M1 (1)
Zhang J , Ko J , Hazen R M , Prewitt C T , American Mineralogist , 78 (1993) p.493-499, High-pressure crystal chemistry of KAlSi3O8 hollandite, Pressure = 4.47 GPa