Citation: Ohta, T.; Takeda, H.; Takeuchi, Y. (1982). Mica polytypism: Similarities in the crystal structures of coexisting 1M and 2M(1) oxybiotite Sample: in the 2M1 setting. American Mineralogist, 67, pp. 298-310.
Formula: Al3.3 Fe3.512 K2 Mg7.164 O48 Si5.68 Ti1.344
List type: noninterleaving
List: 2D
Basis: (1;0;0 0;1;0)
Dimensionality: 2
Formula: Al22 Fe22 Mg6 O40 Si16 Ti4 (Al11 Fe11 Mg3 O20 Si8 Ti2)
Multiplicity: 1