Iranite

for "Iranites" the fossil cephalopod genus see Xenodiscidae
Iranite
General
Category Silicate mineral
Formula
(repeating unit)		 Pb10Cu(CrO4)6(SiO4)2(F,OH)2
Strunz classification 7.FC.15
Crystal system Triclinic
Space group Triclinic pedial
H-M symbol: (1)
Space group: P1
Unit cell a = 10.02 Å, b = 9.54 Å, c = 9.89 Å; α = 104.5°, β = 66°, γ = 108.5°; Z=1
Identification
Color Brown to orange
Crystal habit Equant to flattened euhedral crystals
Mohs scale hardness 3
Luster Vitreous
Streak Yellow
Specific gravity 5.8
Optical properties Biaxial
Refractive index nα = 2.250 - 2.300 nγ = 2.400 - 2.500
Birefringence δ = 0.150 - 0.200
References [1][2][3]

Iranite (Persian: ایرانیت) is a triclinic lead copper chromate silicate mineral with formula Pb10Cu(CrO4)6(SiO4)2(F,OH)2. It was first described from an occurrence in Iran. It is the copper analogue of hemihedrite (Pb10Zn(CrO4)6(SiO4)2(F,OH)2).[2]

It occurs as an oxidation product of hydrothermal lead-bearing veins. Associated minerals include dioptase, fornacite, wulfenite, mimetite, cerussite and diaboleite.[1] It was first described in 1970 for an occurrence in the Sebarz Mine, northeast of Anarak, Iran.[2][1]

References

  1. 1 2 3 Handbook of Mineralogy
  2. 1 2 3 Mindat page for Iranite
  3. ↑ Webmineral data for Iranite
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