Heterosite is an iron manganese phosphate in the Heterosite-Purpurite Series, and a member of the Triphylite Group. It was named in 1826 by Francois Alluaud (II) from the Greek word, "another", in reference to the species being the second new mineral containing iron and manganese from the type locality: Les Hureaux, Saint-Sylvestre, Haute-Vienne, Limousin, France. Heterosite is the trivalent iron end member in the Heterosite-Purpurite Series.Heterosite is a secondary mineral, formed by oxidation of iron and simultaneous leaching of lithium from triphylite. It forms cleavable, blocky masses which are brown-black to purple-black on altered surfaces, with a silky luster. Other notable localities include: Palermo No. 1 mine, Grafton Co., New Hampshire, USA; Tip Top mine and other pegmatites, Custer district, Custer Co., and Keystone, Pennington Co., all South Dakota, USA; Sapucaia, Galilieia, Minas Gerais, Brazil; Otov, near Horsovsky Tun, Bohemia, Czech Rep.; Hagendorf and Huhnerkobel near Zweisel, both Bavaria, Germany; Chanteloube, and Hureaux quarry, St. Silvestre, both Haute-Vienne dept., France; Varutrask, Vassterbotten prov., Sweden; Buranga, Gisenyi prov., Rwanda; Sandamab, and Erongo, both Namibia; Euriowie Range, Broken Hill, New South Wales, Australia. If you want to buy Heterosite crystals or learn about the fine mineral species Heterosite, visit iRocks.com to buy online.