AM_Biotite_28 Formula: Si1.36 Al1.24 Fe1.4 Mg.71 Ti.16 (Na.02 K.98) O12 H1.64 Name: Biotite Unit cell: 5.335 9.242 20.181 90.0 95.2 90.0 , V=990.95 Space group: C12/C1 (15)

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: C6c