Rammelsbergite
(repeating unit)NiAs2 IMA symbol Rmb[1] 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 [2][3][4]
H-M symbol: (2/m 2/m 2/m)
c = 3.539 Å; Z = 2
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.
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).[3]
It occurs as a hydrothermal mineral in medium temperature veins association with skutterudite, safflorite, lollingite, nickeline, native bismuth, native silver, algodonite, domeykite and uraninite.[2]
See also
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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