# Nichromite

> Mediated Wiki article. Canonical URL: https://mediated.wiki/source/Nichromite
> Markdown URL: https://mediated.wiki/source/Nichromite.md
> Source: https://en.wikipedia.org/wiki/Nichromite
> Source revision: 1348971768
> License: Creative Commons Attribution-ShareAlike 4.0 International (https://creativecommons.org/licenses/by-sa/4.0/)

{{Short description|Spinel mineral}}
{{Infobox mineral
|name=Nichromite
|image=Nichromite.jpg| category     = Spinel group
| formula      = {{chem2|(Ni,Co,Fe)(Cr,Fe,Al)2O4}}
| strunz       = 4.BB.05
| system       = [Isometric](/source/Cubic_crystal_system)
| class        = Hexoctahedral (m{{overline|3}}m) <br/>[H-M symbol](/source/H-M_symbol): (4/m {{overline|3}} 2/m)
| symmetry     = ''Fd''{{overline|3}}m
| unit cell    = a = 8.32&nbsp;Å; V = 573.86&nbsp;Å<sup>3</sup>; Z&nbsp;=&nbsp;8
| color        = Dark green, black
| habit        = Granular, anhedral to subhedral
| mohs         = 6-{{frac|6|1|2}}
| fracture     = Conchoidal
| luster       = Metallic
| refractive   =
| opticalprop  = Isotropic
| pleochroism  =
| streak       = Greyish green
| gravity      = 5.10
|diaphaneity  = Opaque
|references=<ref name=Mindat>[http://www.mindat.org/min-2894.html Nichromite on Mindat.org]</ref><ref name=Webmin>[http://webmineral.com/data/Nichromite.shtml  Nichromite on Webmineral]</ref><ref>Sawaokaa,A.,Saitoa,S.,Inoueb,K. and Asadab,T. (1971)Effect of high pressure on the lattice constants of chromites having the spinel structure. Materials Research Bulletin, 6, 97-101.</ref><ref name=Cabri>Cabri, L. J., Chao G.Y., Pabst, Adolf, Fleischer, Michael. (1980) New Mineral Names. American Mineralogist, 65, 811.</ref>
 }}
'''Nichromite''' {{chem2|(Ni,Co,Fe)(Cr,Fe,Al)2O4}}<ref name=Mindat/> is a black [cubic](/source/Cubic_crystal_system) metallic mineral and member of the [spinel](/source/spinel) group.<ref>[http://glossary.agiweb.org/dbtw-wpd/exec/dbtwpub.dll Glossary of Geology]</ref>  Nichromite was originally reported from the Bon Accord nickel deposit in [Barberton District](/source/Barberton%2C_Mpumalanga), [South Africa](/source/South_Africa).<ref name=Mindat/>  Occurring naturally in a nickel deposit, nichromite is named for [chromite](/source/chromite) with dominant [nickel](/source/nickel).<ref name=Webmin/> 

The atomic arrangement of the spinel group is a commonly studied structure and characteristically has four closely packed oxygen atoms.  The nickel atoms are organized corresponding to a "normal" spinel arrangement.<ref>Wyckoff, R.W.G. (1965) Crystal Structures (Second Edition). 75-86 p. University of Arizona, Tucson, Arizona.</ref>  

The mineral has only been found in the Bon Accord Nickel Deposit in South Africa where it is formed by replacing chromite and rimmed by [trevorite](/source/trevorite).<ref name=Cabri/>  

==References==
{{Reflist}}

Category:Spinel group
Category:Cubic minerals
Category:Minerals in space group 227

{{Oxide-mineral-stub}}

---
Adapted from the Wikipedia article [Nichromite](https://en.wikipedia.org/wiki/Nichromite) by Wikipedia contributors ([contributor history](https://en.wikipedia.org/wiki/Nichromite?action=history)). Available under [Creative Commons Attribution-ShareAlike 4.0 International](https://creativecommons.org/licenses/by-sa/4.0/). Changes may have been made.