Bunsenite

(repeating unit)NiOIMA symbolBus[1]Strunz classification4.AB.25Crystal systemCubicCrystal classHexoctahedral (m3m)
H–M symbol: (4/m 3 2/m)Space groupFm3mUnit cella = 4.1769 Å; Z = 4IdentificationColorDark pistachio-greenCrystal habitOctahedral crystal coatings, also cube or dodecahedron formsTwinningObservedCleavageNoneMohs scale hardness5.5LusterVitreousStreakBrownish-blackDiaphaneityTransparentSpecific gravity6.898Optical propertiesIsotropicRefractive indexn = 2.37Other characteristicsVery high reliefReferences[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 nickel–uranium 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]

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. ^ 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