Descloizite
Descloizite is a gem that is extremely rare. Its the zinc-rich end user of the Descloizite-Mottramite series with Mottramitebeing the copper end member that is rich. Descloizite can also be an uncommon and mineral that is attractive to collectors.
Descloizite is available at many localities worldwide including the locality that is sort of de Córdoba, Córdoba, Argentina. At Los Lamentos and Santa Eulalia, Chihuahua, Mexico. In the USA, in the Mammoth-St. Anthony mine, Tiger, Pinal County, and from Bisbee, Cochise County, Arizona; in the Caballo Mountains district, Sierra County, and mines that are several Georgetown, Grant County, New Mexico; through the Chalk Mountain mine, Churchill County, Nevada. Large crystals from a deposit that is economic Berg Aukas, near Grootfontein; at Abenab; from Tsumeb, Namibia. At Kabwe (Broken Hill), Zambia. From M’fouti and Ruwe, Congo Republic. Within the Gowde mine, Great Salt Desert, Iran. At Obir, Carinthia, Austria. From Mežica (Mies), Slovenia. In the Prequica mine, Cabral d’Adrea, Portugal.
| Category: | Vanadate mineral |
| Chemical Formula: | (Pb, Zn)2VO4OH |
| Crystallography: | Orthorhombic – Dipyramidal |
| Crystal Habit: | As crystals, equant or pyramidal, prismatic or tabular, many others, rarely skeletal, to 5 cm, commonly in drusy crusts, stalactitic or botryoidal, coarsely fibrous, granular to compact, massive. |
| Twinning: | None |
| Cleavage: | None observed |
| Fracture: | Irregular/Uneven, Sub-Conchoidal |
| Tenacity: | Brittle |
| Hardness (Mohs): | 3.0 – 3.5 |
| Density: | ~6.20 (g/cm3) |
| Luminescence: | None |
| Radioactivity: | Not Radioactive |
| Other: | Readily soluble in acids |
| Color: | Brownish Red, Red-Orange, Reddish Brown to Blackish Brown, nearly Black. Crystals often exhibit zonal growth with varying colors. |
| Transparency: | Transparent to Opaque |
| Luster: | Greasy |
| Refractive Index: | 2.185 – 2.35 Biaxial ( – ), rarely Biaxial ( + ) |
| Birefringence: | 0.1650 |
| Dispersion: | Strong; r > v, rarely r < v |
| Pleochroism: | Weak to Strong; X = Y = canary-yellow to greenish yellow; Z = brownish yellow |
