Hauerite
Hauerite is a simple Manganese Sulfide that is a fairly rare mineral sought by by mineral collectors for its beautiful reddish black octahedral crystals. There are very few Hauerite mineral specimens available on the market, most are from old classic European collections, but faceted gems are almost impossible to find. It is rarely faceted since it is usually black to reddish black, opaque and does not have a very high polish. But, since there are Black Gem collectors out there, I am including it.
The main sources of Hauerite are Ronneburg Uranium deposit, Gera, Thuringia, Germany; Destricella mine, Raddusa, Catania Province, Sicily, Italy; Olkusz Mine, Olkusz District, Malopolskie, Poland and Jeziórko Mine, Tarnobrzeg, Podkarpackie, Poland. Hauerite is also found in the USA at the Gulf and Big Hill salt domes, Matagorda County; the High Island salt dome, Galveston County; the Boling salt dome, Wharton County; and the Fannett salt dome, Jefferson County, Texas.
| Category: | Sulfide mineral, pyrite group |
| Formula: | MnS2 |
| Manganese(II) sulfide | |
| Crystallography: | Isometric – Diploidal |
| Crystal Habit: | Octahedral crystals common, also cubo-octahedral, to 5 cm; as globular aggregates. |
| Twinning: | None |
| Cleavage: | [100] Perfect, [010] Perfect, [001] Perfect |
| Fracture: | Uneven |
| Tenacity: | Brittle |
| Hardness (Mohs): | 4.0 |
| Density: | 3.463 (g/cm3) |
| Luminescence: | None |
| Radioactivity: | Not Radioactive |
| Color: | Reddish Brown, Brownish Black, Black |
| Transparency: | Opaque |
| Luster: | Metallic, Adamantine |
| Refractive Index: | 2.690 Isotropic |
| Birefringence: | 0.00 Isotropic |
| Dispersion: | n/a |
| Pleochroism: | None |
