Citation: Brigatti, M. F.; Frigieri, P.; Poppi, L. (1998). Crystal chemistry of Mg-, Fe-bearing muscovites-2M1 Sample H87b from peraluminous granites at Sardinia, Italy. American Mineralogist, 83, pp. 775-785.
Formula: Al2.68 F0.04 Fe0.3 K0.96 Na0.04 O11.96 Si3.08
List type: interleaving
List: 2D
Basis: (1;0;0 0;1;0)
Dimensionality: 2
Formula: Al14 F4 Fe4 O24 Si8 (Al7 F2 Fe2 O12 Si4)
Multiplicity: 1