| Chaidamuite | |
| Category: | Sulfate minerals |
| Formula: | ZnFe3+(SO4)2(OH)·4(H2O) |
| Imasymbol: | Cdm[1] |
| Strunz: | 7.DC.30 |
| System: | Triclinic |
| Class: | Pedial (1) (same H-M symbol) |
| Symmetry: | P1 |
| Unit Cell: | a = 7.309(2) Å, b = 7.202(2) Å, c = 9.691(3) Å; α = 89.64(3)°, β = 105.89(1)°, γ = 91.11(1)°; Z = 2 |
| Color: | Brown to yellow-brown |
| Habit: | Tabular pseudocubic crystals and granular masses; pseudomonoclinic |
| Cleavage: | On and, perfect. |
| Fracture: | conchoidal |
| Mohs: | 2.5–3 |
| Luster: | Vitreous |
| Refractive: | nα = 1.632 nβ = 1.640 nγ = 1.688 |
| Opticalprop: | Biaxial (+) |
| Birefringence: | δ = 0.056 |
| 2V: | 44° |
| Pleochroism: | Strong: X= pale yellow, colorless; Y= pale yellow; z= Brownish yellow |
| Streak: | Pale yellow |
| Diaphaneity: | Translucent |
| References: | [2] [3] [4] [5] |
Chaidamuite is a rare zinc – iron sulfate mineral with chemical formula: ZnFe3+(SO4)2(OH)·4H2O.
It was first described for an occurrence in the Xitieshan mine south of Mt. Qilianshan in the Chaidamu basin, Qinghai Province, China and was named for the locality. It occurs as an oxidation phase in a lead zinc deposit. In the type locality it is associated with the rare minerals: coquimbite, copiapite, butlerite and zincobotryogen.[5] In addition to the Chinese occurrence, it has been reported from the Getchell Mine in the Potosi District in Humboldt County, Nevada.[3]