Citation: Brigatti, M. F.; Galli, E.; Poppi, L. (1991). Effect of Ti substitution in biotite-M crystal chemistry Sample 17 from a quartz diorite, Capo Vaticano, Italy. American Mineralogist, 76, pp. 1174-1183.
Formula: Al1.428 Ca0.001 Cr0.006 Fe1.296 K0.914 Mg1.245 Mn0.009 Na0.022 O12 Si2.764 Ti0.198
List type: noninterleaving
List: 2D
Basis: (1;0;0 0;1;0)
Dimensionality: 2
Formula: Al14 Cr6 Fe6 Mg6 Mn6 O24 Si8 Ti6 (Al7 Cr3 Fe3 Mg3 Mn3 O12 Si4 Ti3)
Multiplicity: 1