{{Short description|Sulfide mineral}} {{Infobox mineral | name = Djerfisherite | boxwidth = | boxbgcolor = | image = Djerfisherite.jpg | imagesize = | alt = | caption = Djerfisherite found in Russia | category = Sulfide mineral | formula = See text | IMAsymbol = Djr<ref>{{Cite journal|last=Warr|first=L.N.|date=2021|title=IMA–CNMNC approved mineral symbols|journal=Mineralogical Magazine|volume=85|issue=3|pages=291–320|doi=10.1180/mgm.2021.43|bibcode=2021MinM...85..291W|s2cid=235729616|doi-access=free}}</ref> | molweight = | strunz = 2.FC.05 | system = Cubic | class = Hexoctahedral (m{{overline|3}}m) <br/>H-M symbol: (4/m {{overline|3}} 2/m) | symmetry = ''Pm''{{overline|3}}m | unit cell = a = 10.465&nbsp;Å; Z&nbsp;=&nbsp;1 | colour = | color = Greenish yellow, khaki to olive drab | habit = Rounded grains | twinning = | cleavage = | fracture = | tenacity = | mohs = 3.5 | luster = Submetallic | streak = | diaphaneity = Opaque | gravity = | density = | polish = | opticalprop = Isotropic | refractive = | birefringence = | pleochroism = | 2V = | dispersion = | extinction = | length fast/slow = | fluorescence = | absorption = | melt = | fusibility = | diagnostic = | solubility = | impurities = | alteration = | other = | prop1 = | prop1text = | references = <ref name=Mindat>[http://www.mindat.org/min-1299.html Mindat.org - Djerfisherite]</ref><ref name=HBM>[http://rruff.info/doclib/hom/djerfisherite.pdf Djerfisherite in the Handbook of Mineralogy]</ref><ref name=Webmin>[http://www.webmineral.com/data/Djerfisherite.shtml Djerfisherite data on Webmineral]</ref> }}

'''Djerfisherite''' is an alkali copper–iron sulfide mineral and a member of the djerfisherite group.

The chemical composition is somewhat variable. A Russian study from 1979 on djerfisherite from the Kola Peninsula found the formula {{chem|K|6|Na(Fe,Cu)|24|S|26|Cl}}, but a study in 2007 of samples from Siberia found no detectable sodium and states that the formula {{chem|K|6|(Fe,Cu,Ni)|25|S|26|Cl}} is considered the most appropriate.<ref name=Zaccarini>{{cite journal |display-authors=etal|last1=Federica Zaccarini |title=Djerfisherite in the Guli dunite complex, polar Siberia: a primary or metasomatic phase? |journal=The Canadian Mineralogist |date=2007 |volume=45 |issue=5 |pages=1201–1211 |doi=10.2113/gscanmin.45.5.1201 |bibcode=2007CaMin..45.1201Z |s2cid=129976188 |url=https://rruff.info/doclib/cm/vol45/CM45_1201.pdf}}</ref> Both crystallographic studies have 58 atoms per unit cell. Sulfur atoms are in three nonequivalent locations, containing 12, 6, and 8 atoms per unit cell. The later study put a copper atom where the earlier study put a sodium atom.<ref>{{cite web |title=Djerfisherite |url=http://rruff.geo.arizona.edu/AMS/result.php?mineral=Djerfisherite |website=American Mineralogist Crystal Structure Database |publisher=University of Arizona}}</ref> More information on the structure and other questions is available,<ref name=Zaccarini/> as well as 3-D models.<ref name=Mindat/>

The Webmineral "Mineralogy Database" site gives the "chemical formula" as {{chem|K|6|Na|(Fe|2+|,Cu|,Ni|)|25|S|26|Cl}}, apparently in error, and an "empirical formula" as {{chem|K|6|Na|Fe|2+|19|Cu|4|NiS|26|Cl}}.<ref name=Webmin/>

Djerfisherite is one of the rare and unusual minerals in its chemical composition, combining lithophile (K) and chalcophile (Cu,Fe,Ni) elements in its composition. In addition to djerfisherite itself, such minerals also include sodium chvilevaite Na(Cu,Fe,Zn)<sub>2</sub>S<sub>2</sub> and murunskite K<sub>2</sub>Cu<sub>3</sub>FeS<sub>3</sub>.<ref name="push">''Pushcharovsky D. Yu.'' Mineralogical crystallography. — Moscow: Ministry of Natural Resources and Ecology of the Russian Federation, Geokart, Geos, 2020. — 599 p. ''(in Russian)''</ref>{{rp|174}}

Its type locality is the Kota-Kota meteorite (Marimba meteorite), found in Malawi. It was first described in 1966 and named after professor Daniel Jerome Fisher (1896–1988), University of Chicago.<ref name=Mindat/> It has been reported from meteorites, copper-nickel hydrothermal deposits, skarn, pegmatite, kimberlites and alkalic intrusive complexes. Associated minerals include kamacite, troilite, schreibersite, clinoenstatite, tridymite, cristobalite, daubreelite, graphite, roedderite, alabandite, talnakhite, pentlandite, chalcopyrite, magnetite, valleriite, sphalerite and platinum minerals.<ref name=HBM/>

== References == {{reflist}}

Category:Sulfide minerals Category:Cubic minerals Category:Minerals in space group 221

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