Works of "Research Collection"
Place Collected: Tonkerhoek
Place Collected: Leydsdorp
Place Collected: Grenville
Place Collected: Rio Pardo near Bahia border, northern Minas Gerais
Place Collected: 200 km from Helsingfors
Place Collected: Stiepelman's Cave
Place Collected: Hagendorf
Place Collected: Ruashi Mine
Place Collected: Annaberg Mine