Citation: Hendricks, S. B.; Jefferson, M. E. (1939). Polymorphism of the micas with optical measurements Note: data is reproduced from Jackson and West (1930) Note: Biotite group. American Mineralogist, 24, pp. 729-771.
Formula: Al F H K Mg3 O11 Si3
List type: interleaving
List: 2D
Basis: (1;0;0 0;1;0)
Dimensionality: 2
Formula: Al8 F4 Mg6 O24 Si8 (Al4 F2 Mg3 O12 Si4)
Multiplicity: 1