Djerfisherite
| Djerfisherite | |
|---|---|
 Djerfisherite found in Russia | |
| General | |
| Category | Sulfide mineral |
| Formula (repeating unit) | See text |
| Strunz classification | 2.FC.05 |
| Crystal system | Cubic |
| Crystal class | Hexoctahedral (m3m) H-M symbol: (4/m 3 2/m) |
| Space group | Pm3m |
| Unit cell | a = 10.465 Å; Z = 1 |
| Identification | |
| Color | Greenish yellow, khaki to olive drab |
| Crystal habit | Rounded grains |
| Mohs scale hardness | 3.5 |
| Luster | Submetallic |
| Diaphaneity | Opaque |
| Optical properties | Isotropic |
| References | [1][2][3] |
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 K
6Na(Fe,Cu)
24S
26Cl, but a study in 2007 of a samples from Siberia found no detectable sodium and states that the formula K
6(Fe,Cu,Ni)
25S
26Cl is considered the most appropriate.[4] 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.[5] More information on the structure and other questions is available,[4] as well as 3-D models.[1]
The Webmineral "Mineralogy Database" site gives the "chemical formula" as K
6Na(Fe2+
,Cu,Ni)
25S
26Cl, apparently in error, and an "empirical formula" as K
6NaFe2+
19Cu
4NiS
26Cl.[3]
Its type locality is the Kota-Kota meteorite (Marimba meteorite), Malawi. It was first described in 1966 and named after professor (1896–1988), University of Chicago.[1] 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, , alabandite, talnakhite, pentlandite, chalcopyrite, magnetite, valleriite, sphalerite and platinum minerals.[2]
References[]
- ^ a b c Mindat.org - Djerfisherite
- ^ a b Djerfisherite in the Handbook of Mineralogy
- ^ a b Djerfisherite data on Webmineral
- ^ a b Federica Zaccarini; et al. (2007). "Djerfisherite in the Guli dunite complex, polar Siberia: a primary or metasomatic phase?" (PDF). doi:10.2113/gscanmin.45.5.1201. Cite journal requires
|journal=(help) - ^ "Djerfisherite". American Mineralogist Crystal Structure Database. University of Arizona.
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- Sulfide minerals
- Cubic minerals
- Minerals in space group 221
- Sulfide mineral stubs