AM_Biotite_20
Formula: Si2.808 Al1.207 Fe.4 Mg.512 Mn.007 Ti.067 Na.034 K1.906 O12
Name: Biotite
Unit cell: 5.335 9.244 10.206 90.0 100.08 90.0 , V=495.56
Space group: C12/M1 (12)

Bigi S , Brigatti M F , American Mineralogist , 79 (1994) p.63-72, Crystal chemistry and microstructures of plutonic biotite, Sample 1M from Valle del Cervo syenitic complex