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
General
CategoryMineral
Formula
(repeating unit)		NiAs2
IMA symbolRmb[1]
Strunz classification2.EB.15a
Crystal systemOrthorhombic
Crystal classDipyramidal (mmm)
H-M symbol: (2/m 2/m 2/m)
Space groupPnnm
Unit cella = 4.759 Å, b = 5.797 Å
c = 3.539 Å; Z = 2
Identification
ColorTin white with a faint pinkish hue
Crystal habitRarely as prismatic crystals; commonly massive, granular, radial, fibrous
TwinningOn {101}
CleavageDistinct on {101}
FractureIrregular
TenacityBrittle
Mohs scale hardness5.5-6
LusterMetallic
StreakGrayish black
DiaphaneityOpaque
Specific gravity7.0-7.1
Optical propertiesStrongly anisotropic
PleochroismWeak, yellow to pinkish hue and bluish white
References[2][3][4]

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
  1. Warr, L.N. (2021). "IMA–CNMNC approved mineral symbols". Mineralogical Magazine. 85 (3): 291–320. Bibcode:2021MinM...85..291W. doi:10.1180/mgm.2021.43. S2CID 235729616.
  2. Handbook of Mineralogy
  3. Mindat.org
  4. Webmineral data
  • 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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