Locality: Urals Region, Russia Dimensions: 2.5 cm x 2.5 cm x 1.9 cm 2.5 x 2.5 x 1.9 cm (box). Iridium (variety osmiridium) is the rare variety of iridium rich in osmium. The floor of this thumbnail box is totally covered with a multitude of tiny, splendent, silvery nuggets and flakes. This is a little hoard of this rarity and is seldom available in any quantity. Old-time material that undoubtedly dates to Imperial Russia times, prior to World War I. Ex. Field Museum of Chicago Collection.