Cornwallite
Copper arsenate mineral
(repeating unit)(same H-M symbol)
c = 4.60 Å; β = 92.22°; Z = 2
Cornwallite is an uncommon copper arsenate mineral with formula Cu5(AsO4)2(OH)4. It forms a series with the phosphate pseudomalachite and is a dimorph of the triclinic cornubite. It is a green monoclinic mineral which forms as radial to fibrous encrustations.
![](http://upload.wikimedia.org/wikipedia/commons/thumb/b/ba/Cornwallite-Baryte-54193.jpg/220px-Cornwallite-Baryte-54193.jpg)
Discovery and occurrence
It was first described in 1846, for an occurrence in Wheal Gorland, St Day United Mines of the St Day District, Cornwall, England.[4] It occurs as secondary mineral in the oxidized zone of copper sulfide deposits. Associated minerals include olivenite, cornubite, arthurite, clinoclase, chalcophyllite, strashimirite, lavendulan, tyrolite, spangolite, austinite, conichalcite, brochantite, azurite and malachite.[3]
See also
- Kernowite, another mineral named after Cornwall
References
- ^ 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.
- ^ Mineralienatlas
- ^ a b Cornwallite in the Handbook of Mineralogy
- ^ a b Cornwallite on Mindat.org
- ^ Cornwallite data on Webmineral