AM_Biotite_22 Formula: Si2.72 Al1.62 Fe1.5 Mg.76 Ti.22 (Na.04 K.96) O11.96 F.04 H1.8 Name: Biotite Unit cell: 5.352 9.268 10.255 90.0 100.27 90.0 , V=500.52 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: A4