Tags: Chemical Substance, Mineral.
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 (1880โ1970) who had a long-standing association with the Cerro de Pasco mines.