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. It is trimorphous with matraite and sphalerite.
|Crystal class||Dihexagonal pyramidal (6mm) |
H-M symbol: (6mm)
|Jmol (3D)||Interactive image|
|Color||Brownish black, Orange brown, Reddish brown, Black.|
|Crystal habit||Radial clusters and colloform crusts and masses. Also as tabular crystals|
|Cleavage|| and |
|Fracture||Uneven - irregular|
|Mohs scale hardness||3.5-4|
|Luster||Resinous, brilliant submetallic on crystal faces|
|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|
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. 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.
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):
- Handbook of Mineralogy
- 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 group on Mindat.org