Revoredite

I have a questio:

Is one of the TL for Revoredite really the Ragra Mine in Cerro de Pasco. It seems mineralogically some of the other mines like the Excelsior are a much better fit...

I appreciate any input as I am looking at Revoredite samples from "Cerro de Pasco"...

Frank

The entry for revoredite in the "CATALOGUE OF TYPE MINERAL SPECIMENS":

Amstutz GC, Ramdohr P, De Las Casas F: Bol.Soc.Geol.Peru (1957) 32, p. 25

Peru - Junin Dep. - Cerro de Pasco (near) - Minasragra (in V-ores)

• United Kingdom: NHM-London - Type: T: BM 1965,205
• Switzerland: NMBE-Bern - Type: T: (don. GC Amstutz, 1998)
• USA: NMNH-Washington - Type: T: 113100 (don. U.S.Geol.Surv., 1959)

Revoredite is a natural Pb-As-S glass. Not accepted as a proper species; composition near PbAs4S7; a continous series from Pb2As2S7 to As2S3 seems likely. See Milton C and Ingram B in: Amer.Min.(1959) 44, 1070-1076.

This appears to be the only type locality for revoredite.

I agree with Frank that Minasragra was probably a mistake and that revoredite originally came from elsewhere in Cerro de Pasco. Jaroslav Hyrsl might know.

This sort of mix-up is common in Andean deposits. Wasn't the type locality of canfieldite originally in the literature as "La Paz", when it really came from Colquechaca, hundreds of km further south. And penroseite/blockite was described as being from Colquechaca, which has not even traces of Se in the ores, when it really came from Pacajake. And I've still not been able to find out the definitive type locality of teallite (despite what the literature says about it). :-((

My Revoredite with its documentation is now at the Royal Ontario Museum and no longer mine. I do believe it was Cerro de Pasco, although the person I got it from spent a long time at Quiruvilca. The letter with the specimen gives more details and an Americam Mineralogist ref. It is a lovely black arsenic sulfide glass.