Bunsenite

Bunsenite
Bunsenite with unknown colorless crystals from the collection of the „Verein zur Förderung der Lithothek“, Munich (collection number A022658). Field of view 1 mm. Locality: Kochhütte, Helbra, Mansfeld-Südharz, Saxony-Anhalt, Germany
General
CategoryOxide mineral
Formula
(repeating unit)
NiO
IMA symbolBus[1]
Strunz classification4.AB.25
Crystal systemCubic
Crystal classHexoctahedral (m3m)
H–M symbol: (4/m 3 2/m)
Space groupFm3m
Unit cella = 4.1769 Å; Z = 4
Identification
ColorDark pistachio-green
Crystal habitOctahedral crystal coatings, also cube or dodecahedron forms
TwinningObserved
CleavageNone
Mohs scale hardness5.5
LusterVitreous
StreakBrownish-black
DiaphaneityTransparent
Specific gravity6.898
Optical propertiesIsotropic
Refractive indexn = 2.37
Other characteristicsVery high relief
References[2][3][4][5]

Bunsenite is the naturally occurring form of nickel(II) oxide, NiO. It occurs as rare dark green crystal coatings. It crystallizes in the cubic crystal system and occurs as well formed cubic, octahedral and dodecahedral crystals. It is a member of the periclase group.

It was first described in 1868 for a sample from a hydrothermal nickeluranium vein from Johanngeorgenstadt, Ore Mountains, Saxony, Germany and named for German chemist Robert Bunsen (1811–1899).[3][5] Other occurrences include west of the Scotia talc mine near Bon Accord, Barberton district, Transvaal, South Africa and from Kambalda south of Kalgoorlie, Western Australia. The South African occurrence has evidence of thermal metamorphism of a nickel-rich meteorite.[4] It occurs associated with native bismuth, annabergite, aerugite, xanthiosite in Germany; and with liebenbergite, trevorite, nickeloan serpentine, nickeloan ludwigite, violarite, millerite, gaspeite, nimite and bonaccordite in the South African occurrence.[4]

  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. ^ Mineralienatlas
  3. ^ a b Bunsenite on Mindat.org
  4. ^ a b c "Bunsenite in the Handbook of Mineralogy" (PDF). Archived from the original (PDF) on 2019-05-08. Retrieved 2014-01-25.
  5. ^ a b Bunsenite data on Webmineral