Citation: Brigatti, M. F.; Frigieri, P.; Ghezzo c; Poppi, L. (2000). Crystal chemistry of Al-rich biotites coexisting with muscovites in peraluminous granites Sample: GFS15a. American Mineralogist, 85, pp. 436-448.
Formula: Al1.9 Ba0.01 Ca0.03 F0.32 Fe1.38 H1.56 K0.96 Mg0.73 Na0.02 O11.68 Si2.68 Ti0.14
List type: noninterleaving
List: 2D
Basis: (1;0;0 0;1;0)
Dimensionality: 2
Formula: Al12 F4 Fe6 Mg6 O28 Si8 Ti4 (Al6 F2 Fe3 Mg3 O14 Si4 Ti2)
Multiplicity: 1