AM_Dravite_9 Formula: Na.64 Ca.29 K.01 Mg2.241 Fe1.449 Al5.28 Mn.021 Ti.009 B3 Si6 O30.92 F.08 H3.54 Name: Dravite Unit cell: 15.9875 15.9875 7.2372 90.0 90.0 120.0 , V=1602.00 Space group: R3M (160)

Bosi F , American Mineralogist , 93 (2008) p.1647-1653, Disordering of Fe2+ over octahedrally coordinated sites of tourmaline, Locality: Uto Island, south of Stockholm, Sweden