Hopeite
| Hopeite | |
|---|---|
 Hopeite Belgium – Type locality | |
| General | |
| Category | Phosphate minerals |
| Formula (repeating unit) | Zn3(PO4)2·4H2O |
| IMA symbol | Hop[1] |
| Strunz classification | 8.CA.30 |
| Crystal system | Orthorhombic |
| Crystal class | Dipyramidal (mmm) H-M symbol: (2/m 2/m 2/m) |
| Space group | Pnma |
| Identification | |
| Formula mass | 458.17 g/mol |
| Color | Colorless, gray white, yellow, white, light yellow |
| Crystal habit | Encrustations – Forms crust-like aggregates on matrix. Prismatic – crystals shaped like slender prisms (e.g. tourmaline). Reniform – kidney-like in shape (e.g. hematite). |
| Cleavage | [100] Perfect, [010] good, [001] poor |
| Fracture | Uneven – flat surfaces (not cleavage) fractured in an uneven pattern |
| Mohs scale hardness | 3–3.5 |
| Luster | Vitreous (glassy) |
| Streak | White |
| Specific gravity | 3 |
| Optical properties | Biaxial (−), a = 1.572–1.574, b = 1.582–1.591, g = 1.59–1.592 |
| Other characteristics | Non-radioactive, non-magnetic |
Hopeite is a hydrated zinc phosphate with formula: Zn3(PO4)2·4H2O. It is a rare mineral used mainly as a collectors specimen.
Hopeite crystallizes in the orthorhombic system with prismatic, vitreous white to yellow crystals. It also forms druzy encrustations and reniform (kidney-shaped) masses. The related mineral parahopeite, which has the same composition but different crystal structure, is triclinic. The minerals are formed through oxidation of sphalerite by the presence of phosphate-rich solutions.
It was first described in 1822 from Moresnet, Liège Province, Belgium and is named after Scottish chemist, Thomas Charles Hope (1766–1844) of the University of Edinburgh.
It has been found in Zambia associated with lazulite.
Hopeite is one of the two conversion minerals arising from the application of the rust converter 'Fertan'.[2]
References
[edit]- ^ Warr, L.N. (2021). "IMA–CNMNC approved mineral symbols". Mineralogical Magazine. 85 (3): 291–320. Bibcode:2021MinM...85..291W. doi:10.1180/mgm.2021.43. S2CID 235729616.
- ^ "Fertan Rust Destroyer from Autorepaired". Archived from the original on 2017-10-21. Retrieved 2022-04-15.
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