| Gratonite | |
|---|---|
 Gratonite, Excelsior Mine, Cerro de Pasco, Peru, the type locality. 1.7 x 1.6 x 1.5 cm. | |
| 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 |
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, Peru. [2] 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 Riotinto mine, Minas de Riotinto (Huelva), Spain. The crystals are very similar to those from Cerro de Pasco.[3]
- ^ Warr, L.N. (2021). "IMA–CNMNC approved mineral symbols". Mineralogical Magazine. 85 (3): 291–320. Bibcode:2021MinM...85..291W. doi:10.1180/mgm.2021.43. S2CID 235729616.
- ^ Palache, C. and Fisher, D.J. (1940). "Gratonite - A new mineral from Cerro de Pasco". American Mineralogist. 25: 255–265.
{{cite journal}}: CS1 maint: multiple names: authors list (link) - ^ Calvo Rebollar, Miguel (2003). Minerales y Minas de España. Vol. II. Sulfuros y sulfosales [Minerals and mines of Spain] (in Spanish). Vitoria, Spain: Museo de Ciencias Naturales de Alava. pp. 590–591. ISBN 978-84-7821-543-0.