Hopeite

Mineral
(repeating unit)Zn3(PO4)2·4H2OIMA symbolHop[1]Strunz classification8.CA.30Crystal systemOrthorhombicCrystal classDipyramidal (mmm)
H-M symbol: (2/m 2/m 2/m)Space groupPnmaIdentificationFormula mass458.17 g/molColorColorless, gray white, yellow, white, light yellowCrystal habitEncrustations – 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] poorFractureUneven – flat surfaces (not cleavage) fractured in an uneven patternMohs scale hardness3–3.5LusterVitreous (glassy)StreakWhiteSpecific gravity3Optical propertiesBiaxial (−), a = 1.572–1.574, b = 1.582–1.591, g = 1.59–1.592Other characteristicsNon-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

  1. ^ 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.
  2. ^ "Fertan Rust Destroyer from Autorepaired". Archived from the original on 2017-10-21. Retrieved 2022-04-15.
  • Mindat with location data
  • Mineral galleries
  • Webmineral data
Orange-brown hopeite prisms to 3 mm on a nearly solid matrix of glassy, pastel yellow-green parahopeite crystals. Locality: Kabwe Mine (Broken Hill Mine), Kabwe, Central Province, Zambia. Broken Hill is the type locality for parahopeite.
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