Gratonite is a lead-arsenic sulfosalt mineral, with the chemical composition Pb₉As₄S₁₅. It is considered a low-temperature dimorph of jordanite. Gratonite was discovered in 1939 at the Excelsior Mine,

Cerro de Pasco Cerro de Pasco is a city in central Peru, located at the top of the Andean Mountains. It is the capital of both the Pasco Province and the Department of Pasco, and an important mining center of silver, copper, zinc and lead. At an elevation of ...

Peru Peru, officially the Republic of Peru, is a country in western South America. It is bordered in the north by Ecuador and Colombia, in the east by Brazil, in the southeast by Bolivia, in the south by Chile, and in the south and west by the Pac ...

. It is named in honor of geologist L. C. Graton (1880–1970), who had a long-standing association with the Cerro de Pasco mines. The other location where it is found is the Rio Tinto mine, Minas de Riotinto (Huelva), Spain. The crystals are very similar to those from Cerro de Pasco.

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Mineral Data PublishingWebmineral
Lead minerals Arsenic minerals Sulfide minerals Trigonal minerals Minerals in space group 160 {{sulfide-mineral-stub