Very small single crystal of the extremely rare mineral chromferide, a natural alloy of chromium and iron of formula Fe3Cr (1-x). It belongs to the Nickel-Strunz class of I.Native Elements. Analyzed specimen. Chromferide has only been known from three localities worldwide, being this one from the type locality in Russia: Efim Area, Kumak Ore Field, Urals Region, Russian Federation. — Photo: David Hospital · CC BY-SA 4.0
Chromferide
Chromferide is an IMA-recognized mineral species in the native element class, with the chemical formula Fe₁.₅Cr₀.₂.
It crystallizes in the cubic crystal system (space group Pm3m). It is a member of the Iron structural group.
Key properties: specific gravity 6.69; Metallic. R: (400) —, (420) —, (440) 50.4, (460) 51.4, (480) 50.9, (500) 52.6, (520) 53.0, (540) 55.3, (560) 56.5 luster.
IMA symbol Cfe, IMA status: approved, named in 1984.
Found in quartz veins within brecciated amphibolites and schist.
It is found associated with Iron, copper, bismuth, gold, ferchromide, graphite, cohenite, halite, sylvite, marialite, quartz.
The name refers to the chemical composition, CHROMium and FERrum, iron.