AM_Schorl_4 Formula: Ca.48 K.01 Na.49 Mg2.19 Ti.21 Fe2.04 Al4.56 Si6 B3 O30.82 F.18 H6.18 Name: Schorl Unit cell: 16.017 16.017 7.256 90.0 90.0 120.0 , V=1612.09 Space group: R3M (160)

Camara F , Ottolini L , Hawthorne F C , American Mineralogist , 87 (2000) p.1437-1442, Crystal chemistry of three tourmalines by SREF, EMPA and SIMS, Sample: Crystal 1 from Madagascar, Note: intermediate between feruvite and schorl