These samples of sperrylite are displayed in the Smithsonian Museum of Natural History. Sperrylite is a compound of platinum and arsenic with the composition PtAs2. The sample at left is about 6x9 cm and is from Pottgietersrust, Transvaal, South Africa. The one at right is about 5x6 cm and is from Talnach deposit, Noril'sk, Krasnoyarskiy Kray, Russia. The one at right also contains chalcopyrite and pentlandite.