Thursday, June 24, 2010

Barite from Goldfield

Continuing down the pallet at Goldfield, NV, I spotted this huge rock made almost entirely of barite.
This is hydrothermal barite, not the bedded barite often mined for barite drilling mud (with Nevada being the largest producer in the U.S., and third after China and India worldwide in 2008).
Here's a closeup photo showing nice orthorhombic barite crystals coated with tiny druses (quartz?). Barite is often first noticed because of its high specific gravity – it's very heavy compared to other minerals and hand samples – and it doesn't fizz in HCl the way calcite and limestone do.

I've got some nice barite crystals from the Northumberland gold mine, tucked away in a box somewhere. The particular small pit my crystals came from has long since been mined.

More About Barite:
Jewell, P. W., 2000, Bedded barite in the geologic record: SEPM Special Publication, v. 66, p. 147-161 [link to abstract].

Jewell, P. W., and Stallard, R. F., 1991, Geochemistry and Paleoceanographic Setting of Central Nevada Bedded Barites: Journal of Geology, v. 99, p. 151-170 [link to abstract].

Nevada—2007: USGS Minerals Yearbook, Volume II, Area Reports: Domestic.

Rossi Mine - Barite, Elko County, Nevada – with photos of bedded and crystalline barite.

Goldfield series so far:
Headframes of Goldfield
Alunite from Goldfield
Pyrophyllite from Goldfield
Barite from Goldfield (this post)
Enargite from Goldfield

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