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.