Wurtzite

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Wurtzite
Wurtzite mineral.jpg
General
Category Sulfide mineral
Formula
(repeating unit)
(Zn,Fe)S
Strunz classification 02.CB.45
Dana classification 02.08.07.01
Identification
Color Brownish black, Orange brown, Reddish brown, Black.
Crystal habit Radial clusters and colloform crusts and masses. Also as tabular crystals
Crystal system Hexagonal dihexagonal pyramidal H-M symbol (6mm) Space group: P63mc
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]
This article is about the mineral wurtzite. For the wurtzite crystal structure, see Wurtzite (crystal structure).

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]

Wurtzite unit cell. The grey balls represent metal atoms, and yellow balls represent sulfur or selenium atoms.

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 ABBABBABB pattern.

The unit cell parameters of wurtzite are (-2H polytype):[2]

  • a = b = 3.82 Å = 382 pm
  • c = 6.26 Å = 626 pm
  • V = 79.11 Å3
  • Z = 2

References[edit]

  1. ^ a b c d Handbook of Mineralogy
  2. ^ a b c Wutzite at Mindat.org
  3. ^ Wurtzite at Webmineral
  4. ^ 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.
  5. ^ Wutzite at Mindat.org

External links[edit]