AM_Biotite_15
Formula: Si2.868 Al1.282 K.955 Ca.013 Na.03 Mg1.899 Cr.072 Fe.504 Mn.027 Ti.324 O12
Name: Biotite
Unit cell: 5.315 9.204 10.168 90.0 100.13 90.0 , V=489.66
Space group: C12/M1 (12)

Brigatti M F , Galli E , Poppi L , American Mineralogist , 76 (1991) p.1174-1183, Effect of Ti substitution in biotite-M crystal chemistry, Sample 11 from a lamproite rock, Jummilla, Spain