Walfordite
Walfordite | |
---|---|
Walfordite from Tambo Mine, Elqui Province, Chile | |
General | |
Category | Tellurite minerals |
Formula (repeating unit) | Fe3+,Te6+Te4+3O8 |
Strunz classification | 4.JK.05 |
Crystal system | Isometric |
Space group | I2, Ia3 |
Unit cell | a = 11.011 Å ; Z = 8 |
Identification | |
Colour | Orange |
Crystal habit | Microscopic cubic crystals |
Cleavage | None |
Tenacity | Brittle |
Luster | Adamantine |
Streak | Orange-yellow |
Diaphaneity | Opaque |
Specific gravity | 5.841 (calculated) |
Optical properties | Isotropic |
Refractive index | n = 2.23 |
References | [1][2][3] |
Walfordite is a rare tellurite mineral that was discovered in Chile in 1999.[4] The mineral is described as orange with orange-yellow streak, and is determined to have a chemical formula of Fe3+,Te6+Te4+3O8[1] with minor titanium and magnesium substitution resulting in an approximate empirical formula of (Fe3+,Te6+,Ti4+,Mg)(Te4+)3O8.[4]
Occurrence
The only reported occurrence[2] is in the Wendy open pit, El Indio-Tambo mining district of Coquimbo Region, northern Chile where it occurs in oxidized breccia associated with a tellurium-bearing gold deposit. Associated minerals include: alunite, rodalquilarite, native gold, emmonsite, jarosite and pyrite. The mineral was named for mine geologist Phillip Walford (1945— ) who first noted the mineral.[1]
References
- 1 2 3 Walfordite in the Handbook of Mineralogy
- 1 2 Walfordite on Mindat.org
- ↑ Walfordite data on Webmineral
- 1 2 Back, Malcolm E.; Grice, Joel D.; Gault, Robert A.; Criddle, Alan J.; Mandarino, Joseph A. (1999). "Walfordite, a New Tellurite Species from the Wendy Open Pit, El Indio - Tambo Mining Property, Chile" (PDF). The Canadian Mineralogist. 37: 1261–1268.
This article is issued from Wikipedia - version of the 10/19/2016. The text is available under the Creative Commons Attribution/Share Alike but additional terms may apply for the media files.