| Wurtzite | |
| Category: | Sulfide mineral |
| Imasymbol: | Wur[1] |
| Strunz: | 2.CB.45 |
| Dana: | 02.08.07.01 |
| System: | Hexagonal |
| Class: | Dihexagonal pyramidal (6mm) H-M symbol: (6mm) |
| Symmetry: | P63mc |
| Color: | Brownish black, orange brown, reddish brown, black |
| Habit: | Radial clusters and colloform crusts and masses. Also as tabular crystals |
| Cleavage: | [11{{overline|2}}0] and [0001] |
| Fracture: | Uneven – irregular |
| Mohs: | 3.5–4 |
| Luster: | Resinous, brilliant submetallic on crystal faces |
| Refractive: | nω = 2.356 nε = 2.378 |
| Opticalprop: | Uniaxial (+) |
| Birefringence: | δ = 0.022 |
| Streak: | light brown |
| Gravity: | 4.09 measured, 4.10 calculated |
| Diaphaneity: | Translucent |
| Other: | Nonmagnetic, non-radioactive |
| References: | [2] [3] [4] |
| Smiles: | [ZnH2-2]1[S+2]47[ZnH-2]2[S+2][ZnH-2]3[S+2]8([ZnH2-2][SH+2]([ZnH2-2]4)[ZnH2-2]6)[ZnH-2]4[S+2][ZnH-2]5[S+2]6([ZnH2-2]6)[Zn-2]78[S+2]78[ZnH-2]([SH+2]69)[SH+2]5[ZnH2-2][SH+2]4[ZnH-2]7[SH+2]3[ZnH2-2][SH+2]2[ZnH-2]8[SH+2]1[ZnH2-2]9 |
| Jmol: | [ZnH2-2]1[SH+2]([ZnH2-2]6)[ZnH2-2][SH+2]7[ZnH-2]2[S+2][Zn-2]3([S+2][ZnH-2]9[S+2]5)[S+2]18[Zn-2]45[S+2][ZnH-2]5[SH+2]6[Zn-2]78[S+2]78[ZnH2-2][SH+2]5[ZnH2-2][S+2]4([ZnH2-2][SH+2]9[ZnH2-2]4)[ZnH-2]7[S+2]34[ZnH2-2][SH+2]2[ZnH2-2]8 |
Wurtzite is a zinc and iron sulfide mineral with the chemical formula, a less frequently encountered structural polymorph form of sphalerite. The iron content is variable up to eight percent.[5] It is trimorphous with matraite and sphalerite.[2]
It occurs in hydrothermal deposits associated with sphalerite, pyrite, chalcopyrite, barite and marcasite. It also occurs in low-temperature clay-ironstone concretions.[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 chemist Charles-Adolphe Wurtz.[3] It has widespread distribution. In Europe it is reported from Příbram, Czech Republic; Hesse, Germany; and Liskeard, Cornwall, England. In the US it is reported from Litchfield County, Connecticut; Butte, Silver Bow County, Montana; at Frisco, Beaver County, Utah; and from the Joplin district, Jasper County, Missouri.[2]
The wurtzite group includes cadmoselite (CdSe), greenockite (CdS), mátraite (ZnS), and rambergite (MnS), in addition to wurtzite.[6]
Its crystal structure is called the wurtzite crystal structure, to which it lends its name. This structure is a member of the hexagonal crystal system and consists of tetrahedrally coordinated zinc and sulfur atoms that are stacked in an ABABABABAB pattern.
The unit cell parameters of wurtzite are (-2H polytype):[7]