Citation: Brigatti, M. F.; Galli, E.; Poppi, L. (1991). Effect of Ti substitution in biotite-M crystal chemistry Sample 10 from a lamproite rock, Fortuna, Spain. American Mineralogist, 76, pp. 1174-1183.
Formula: Al1.161 Ca0.004 Cr0.054 Fe0.588 K0.958 Mg1.602 Mn0.03 Na0.016 O12 Si2.932 Ti0.522
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