Cassiterite with Muscovite
Small Cabinet, 5.8 x 5.1 x 3.8 cm
Annie Mitchell property (Coosa Cassiterite Corp. No. 1 mine), Rockford District, Coosa Co., Alabama
Ex. Dr. Robert Cook
Fantastic cassiterite crystal from an unexpected locality! This remarkable dark brown-red crystal with textbook form is terminated almost exclusively by steep tetragonal forms making it pseudo-octahedral in appearance. Growth hillocks on the faces impart an additional geometric attribute to the crystal. This is from the McAllister Sn-Ta pegmatite discovered in 1982 and represents the first highly fractionated rare element pegmatite in Alabama according to Foord and Cook (1989). Ex. Dr. Robert Cook collection with label and self-collected by him during his exploration work.