AM_Hydroxy-dravite_1 Formula: Na.479 Ca.335 K.01 Mg2.715 Al5.628 V.504 Cr.159 Ti.039 Fe.003 Si5.952 B3 O30.946 F.054 H.507 Name: Hydroxy-dravite Unit cell: 15.9521 15.9521 7.2167 90.0 90.0 120.0 , V=1590.40 Space group: R3M (160)

Bosi F , Lucchesi S , European Journal of Mineralogy , 16 (2004) p.335-344, Crystal chemistry of the schorl-dravite series, Note: Tourmaline TM507e, Locality: Olkhon (Lake Baikal), Siberia