| Walfordite | |
| Category: | Tellurite minerals |
| Formula: | Fe3+,Te6+Te4+3O8 |
| Imasymbol: | wfd[1] |
| Strunz: | 4.JK.05 |
| System: | Isometric |
| Symmetry: | I2, Ia3 |
| Unit Cell: | a = 11.011 Å ; Z = 8 |
| Colour: | Orange |
| Habit: | Microscopic cubic crystals |
| Cleavage: | None |
| Tenacity: | Brittle |
| Luster: | Adamantine |
| Streak: | Orange-yellow |
| Diaphaneity: | Opaque |
| Gravity: | 5.841 (calculated) |
| Opticalprop: | Isotropic |
| Refractive: | n = 2.23 |
| References: | [2] [3] [4] |
Walfordite is a very rare tellurite mineral that was discovered in Chile in 1999.[5] The mineral is described as orange with orange-yellow streak, and is determined to have a chemical formula of Fe3+,Te6+Te4+3O8[2] with minor titanium and magnesium substitution resulting in an approximate empirical formula of (Fe3+,Te6+,Ti4+,Mg)(Te4+)3O8.[5]
The only reported occurrence[3] is in the Wendy open pit, El Indio-Tambo mining district of the 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.