Wurtzite
| Wurtzite | |
|---|---|
 | |
| General | |
| Category | Sulfide mineral |
| Formula (repeating unit) | (Zn,Fe)S |
| 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 |
| 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 | [1][2][3] |
Wurtzite is a zinc iron sulfide mineral ((Zn,Fe)S) a less frequently encountered mineral form of sphalerite. The iron content is variable up to eight percent.[4] It is trimorphous with matraite and sphalerite.[1]
It occurs in hydrothermal deposits associated with sphalerite, pyrite, chalcopyrite, barite and marcasite. It also occurs in low-temperature clay-ironstone concretions.[1]
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.[2] 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.[1]
Wurtzite structure[edit]
The wurtzite group includes: Cadmoselite CdSe, Greenockite CdS, Mátraite ZnS and Rambergite MnS, in addition to wurtzite.[5]
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):[2]
See also[edit]
References[edit]
- ^ a b c d Handbook of Mineralogy
- ^ a b c Wurtzite at Mindat.org
- ^ Wurtzite at Webmineral
- ^ Palache, Charles, Harry Berman & Clifford Frondel (1944), The System of Mineralogy of James Dwight Dana and Edward Salisbury Dana, Yale University 1837-1892, Volume I: Elements, Sulfides, Sulfosalts, Oxides. John Wiley and Sons, Inc., New York. 7th edition, revised and enlarged, pp. 226-228.
- ^ Wurtzite at Mindat.org
