Category Sulfosalt minerals Strunz classification 2.JB.55 Space group R3m | Formula(repeating unit) Pb9As4S15 Crystal system Trigonal | |
 | ||
Crystal class Ditrigonal pyramidal (3m)(same H-M symbol) | ||
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.
References
Gratonite Wikipedia(Text) CC BY-SA