AM_Biotite_27 Formula: Si2.64 Al1.9 Fe1.44 Mg.84 Ti.16 (Na.05 K.95) O12 H1.54 Name: Biotite Unit cell: 5.336 9.239 10.2 90.0 100.29 90.0 , V=494.77 Space group: C12/M1 (12)

Brigatti M F , Frigieri P , Ghezzo c , Poppi L , American Mineralogist , 85 (2000) p.436-448, Crystal chemistry of Al-rich biotites coexisting with muscovites in, peraluminous granites, Sample: B1