| Utahite | |
| Category: | Tellurate minerals |
| Formula: | Cu5Zn3(Te6+O4)4(OH)8·7H2O |
| Imasymbol: | Uta[1] |
| Molweight: | 1,542.46 g/mol |
| Strunz: | 7.DE.25 |
| System: | Triclinic Unknown space group |
| Unit Cell: | a = 8.794 Å, b = 9.996 Å c = 5.66 Å; α = 104.1° β = 90.066°, γ = 96.3333°; Z = 1 |
| Color: | Pale blue, greenish blue |
| Habit: | Prismatic thin tabular to bladed crystals; as sheaves and bow tielike clusters |
| Cleavage: | none |
| Fracture: | Brittle – uneven |
| Mohs: | 4–5 |
| Luster: | Vitreous to pearly |
| Streak: | Pale blue |
| Diaphaneity: | Translucent |
| Gravity: | 5.33 |
| Opticalprop: | Biaxial |
| Refractive: | nα = 1.830 – 1.840 nβ = 1.830 – 1.900 nγ = 1.880 – 1.900 |
| Birefringence: | δ = 0.050 – 0.060 |
| Dispersion: | Strong |
| References: | [2] [3] [4] |
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.
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.[4] It has also been reported from the Empire Mine in the Tombstone District of Cochise County, Arizona.[3]