Iranite
| Iranite | |
|---|---|
| General | |
| Category | Silicate mineral |
| Formula | Pb10Cu(CrO4)6(SiO4)2(F,OH)2 |
| IMA symbol | Irn |
| 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 | |
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).
It occurs as an oxidation product of hydrothermal lead-bearing veins. Associated minerals include dioptase, fornacite, wulfenite, mimetite, cerussite and diaboleite. It was first described in 1970 for an occurrence in the Sebarz Mine, northeast of Anarak, Iran.