Gratonite is a lead-arsenic sulfosalt mineral, with the chemical composition Pb9As4S15. Gratonite was discovered in 1939 at the Excelsior Mine, Cerro de Pasco, Peru. It is named in honor of geologist L. C. Graton (1880–1970), who had a long-standing association with the Cerro de Pasco mines.
Gratonite | |
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General | |
Category | Sulfosalt minerals |
Formula (repeating unit) | Pb9As4S15 |
IMA symbol | Gtn[1] |
Strunz classification | 2.JB.55 |
Crystal system | Trigonal |
Crystal class | Ditrigonal pyramidal (3m) (same H-M symbol) |
Space group | R3m |