AM_Muscovite-3T_2 Formula: (K.9 Na.06 Ca.02 Ba.02) Al2.53 Fe.08 Mg.08 Ti.01 Si3.3 O12 H2 Name: Muscovite-3T Unit cell: 5.1963 5.1963 29.9705 90.0 90.0 120.0 , V=700.83 Space group: P3112 (151)

Guven N , Burnham C W , Zeitschrift fur Kristallographie , 125 (1967) p.163-183, The crystal structure of 3T muscovite, Locality: in granodiorite near Sunrise Copper Prospect, Sultan Basin,, Snohomish County, Washington, USA