Citation: Brigatti, M. F.; Davoli, P. (1990). Crystal-structure refinement of 1M plutonic biotites sample M13 from a granite in the Valle del Cervo pluton. American Mineralogist, 75, pp. 305-313.
Formula: Al Fe K Mg2 O12 Si3
List type: noninterleaving
List: 2D
Basis: (1;0;0 0;1;0)
Dimensionality: 2
Formula: Al8 Fe2 Mg4 O24 Si8 (Al4 Fe Mg2 O12 Si4)
Multiplicity: 1