Citation: Brigatti, M. F.; Galli, E.; Poppi, L. (1991). Effect of Ti substitution in biotite-M crystal chemistry Sample 8 from a lamproite rock, Puebla De Mula, Spain. American Mineralogist, 76, pp. 1174-1183.
Formula: Al1.369 Ca0.03 Cr0.048 Fe0.39 K0.955 Mg2.166 Mn0.021 Na0.015 O12 Si2.856 Ti0.144
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