Rammelsbergite
Rammelsbergite is a nickel arsenide mineral with formula NiAs2. It forms metallic silvery to tin white to reddish orthorhombic prismatic crystals, and is usually massive in form. It has a Mohs hardness of 5.5 and a specific gravity of 7.1.
| Rammelsbergite | |
|---|---|
 Rammelsbergite | |
| General | |
| Category | Mineral |
| Formula (repeating unit) | NiAs2 |
| Strunz classification | 2.EB.15a |
| Crystal system | Orthorhombic |
| Crystal class | Dipyramidal (mmm) H-M symbol: (2/m 2/m 2/m) |
| Space group | Pnnm |
| Unit cell | a = 4.759 Å, b = 5.797 Å c = 3.539 Å; Z = 2 |
| Identification | |
| Color | Tin white with a faint pinkish hue |
| Crystal habit | Rarely as prismatic crystals; commonly massive, granular, radial, fibrous |
| Twinning | On {101} |
| Cleavage | Distinct on {101} |
| Fracture | Irregular |
| Tenacity | Brittle |
| Mohs scale hardness | 5.5-6 |
| Luster | Metallic |
| Streak | Grayish black |
| Diaphaneity | Opaque |
| Specific gravity | 7.0-7.1 |
| Optical properties | Strongly anisotropic |
| Pleochroism | Weak, yellow to pinkish hue and bluish white |
| References | [1][2][3] |
It was first described in 1854 from its type locality in the Schneeberg District in Saxony, Germany. It was named after the German chemist and mineralogist, Karl Friedrich August Rammelsberg (1813–1899).[2]
It occurs as a hydrothermal mineral in medium temperature veins association with skutterudite, safflorite, lollingite, nickeline, native bismuth, native silver, algodonite, domeykite and uraninite.[1]
References
- Mineral Galleries
- Schumann, Walter (1991). Mineralien aus aller Welt. BLV Bestimmungsbuch (2 ed.). p. 223. ISBN 978-3-405-14003-8.
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