AM_Schorl Formula: Na.54 Fe1.902 Al6.966 B3 Si5.856 O30.333 H3 Name: Schorl Unit cell: 15.963 15.963 7.148 90.0 90.0 120.0 , V=1577.41 Space group: R3M (160)

Foit F F , American Mineralogist , 74 (1989) p.422-431, Crystal chemistry of alkali-deficient schorl and tourmaline structural, relationships