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Utahite is an extremely rare secondary copper zinc tellurate mineral found as a product of oxidation. Its chemical formula is Cu5Zn3(Te6+O4)4(OH)8•7H2O.

Utahite
Jarosite-Natrojarosite-pas-129a.jpg
Utahite and Jarosite
General
CategoryTellurate minerals
Formula
(repeating unit)
Cu5Zn3(Te6+O4)4(OH)8•7H2O
Strunz classification7.DE.25
Crystal systemTriclinic
Unknown space group
Unit cella = 8.794 Å, b = 9.996 Å
c = 5.66 Å; α = 104.1°
β = 90.066°, γ = 96.3333°; Z = 1
Identification
Formula mass1,542.46 g/mol
ColorPale blue, greenish blue
Crystal habitPrismatic thin tabular to bladed crystals; as sheaves and bow tielike clusters
Cleavagenone
FractureBrittle - uneven
Mohs scale hardness4-5
LusterVitreous to pearly
StreakPale blue
DiaphaneityTranslucent
Specific gravity5.33
Optical propertiesBiaxial
Refractive indexnα = 1.830 - 1.840 nβ = 1.830 - 1.900 nγ = 1.880 - 1.900
Birefringenceδ = 0.050 - 0.060
DispersionStrong
References[1][2][3]

It was first described in 1997 for an occurrence in the Centennial Eureka mine, one mile southeast of Eureka, Tintic District, Juab County, Utah, US (type locality). The discovery site was a mine dump of a hydrothermal ore deposit where it occurs with cesbronite and quartz.[3] It has also been reported from the Empire Mine in the Tombstone District of Cochise County, Arizona.[2]

ReferencesEdit

  1. ^ Utahite, Webmineral.com
  2. ^ a b Utahite, Mindat.org
  3. ^ a b Handbook of Mineralogy