| Wurtzite | |
|---|---|
 | |
| General | |
| Category | Sulfide mineral |
| Formula | (Zn,Fe)S |
| IMA symbol | Wur[1] |
| Strunz classification | 2.CB.45 |
| Dana classification | 02.08.07.01 |
| Crystal system | Hexagonal |
| Crystal class | Dihexagonal pyramidal (6mm) H-M symbol: (6mm) |
| Space group | P63mc |
| Structure | |
| Jmol(3D) | Interactive image |
| Identification | |
| Color | Brownish black, orange brown, reddish brown, black |
| Crystal habit | Radial clusters and colloform crusts and masses. Also as tabular crystals |
| Cleavage | [1120] and [0001] |
| Fracture | Uneven – irregular |
| Mohs scale hardness | 3.5–4 |
| Luster | Resinous, brilliant submetallic on crystal faces |
| Streak | light brown |
| Diaphaneity | Translucent |
| Specific gravity | 4.09 measured, 4.10 calculated |
| Optical properties | Uniaxial (+) |
| Refractive index | nω = 2.356 nε = 2.378 |
| Birefringence | δ = 0.022 |
| Other characteristics | Nonmagnetic, non-radioactive |
| References | [2][3][4] |
Wurtzite is azinc andironsulfide mineral with the chemical formula(Zn,Fe)S, a less frequently encounteredstructural polymorph form ofsphalerite. The iron content is variable up to eight percent.[5] It is trimorphous withmatraite and sphalerite.[2]
It occurs inhydrothermal deposits associated with sphalerite,pyrite,chalcopyrite,barite andmarcasite. It also occurs in low-temperatureclay-ironstoneconcretions.[2]
It was first described in 1861 for an occurrence in the San José Mine,Oruro City,Cercado Province,Oruro Department,Bolivia, and named for French chemistCharles-Adolphe Wurtz.[3] It has widespread distribution. In Europe it is reported fromPříbram,Czech Republic;Hesse,Germany; andLiskeard,Cornwall,England. In the US it is reported fromLitchfield County, Connecticut; Butte,Silver Bow County, Montana; at Frisco,Beaver County, Utah; and from the Joplin district,Jasper County, Missouri.[2]
The wurtzite group includescadmoselite (CdSe),greenockite (CdS), mátraite (ZnS), andrambergite (MnS), in addition to wurtzite.[6]
Itscrystal structure is called thewurtzite crystal structure, to which it lends its name. This structure is a member of thehexagonalcrystal system and consists of tetrahedrally coordinatedzinc andsulfur atoms that are stacked in an ABABABABAB pattern.
The unit cell parameters of wurtzite are (-2H polytype):[7]