Brochantite


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Related to Brochantite: cuprite

Broch´an`tite


n.1.(Min.) A basic sulphate of copper, occurring in emerald-green crystals.
References in periodicals archive ?
QEMSCAN analysis of the copper ore fragments indicate that oxidized copper minerals corresponding to malachite, chrysocolla and brochantite have been smelted in the furnaces.
1, almost all the diffraction peaks of the precursor could be indexed to Brochantite [Cu4(SO4)(OH)6] and Posnjakite [Cu4(SO4)(OH)6.H2O] which are in good agreement with the standard XRD data (JCPDS card No.
Also, since February 2010 the Milpillas mine has turned out what may be the world's finest brochantite specimens, with lustrous, lushly deep green, thin-prismatic crystals to 5 cm in masses and matted aggregates to 30 cm across.
Copper minerals are atacamite and brochantite in the oxide zone; chalcocite, covellite, and pyrite in the enriched zone; and chalcopyrite, bornite, molybdenite, tennantite, and pyrite in the hypogene zone.
Economic ore types in both deposits can be classified into four major groups: primary sulphides (chalcopyrite and bornite); secondary sulphides (chalcocite, chalcopyrite, bornite, and covellite); oxides (chrysocolla, brochantite); and a mixture of oxide and sulphide.
The principal copper minerals in these remnant zones are neotocite (copper-bearing iron/manganese oxide complex) and minor brochantite and chrysocolla.
This corrosion eventually leads to the formation of a green patina, usually a copper sulfate mineral called brochantite ([Cu.sub.4][(OH).sub.6][SO.sub.4]).
These include arsentsumebite, tsumebite, corkite, fornacite, duftite, caledonite, kettnerite, linarite, leadhillite, brochantite, mimetite, pyromorphite, vanadinite and wulfenite.
The original deposit possessed a leached capping of oxide ore averaging some 27 m in thickness, the principal minerals being malachite, azurite, cuprite, tennantite, brochantite, antlerite and chrysocolla.
X-ray diffraction studies show thatthe green patina consists largely of two basic copper sulfates: brochantite, CuSO.sub.4..3Cu(OH).sub.2., and antlerite, CuSO.sub.4..2Cu(OH).sub.2.
In the same small zone in the Cumbres lugar of the Ojuela mine which produced the claringbullite, a few specimens of tenorite pseudomoiphs after paramelaconite were found as microcrystals, as well as brochantite.
Baboian's results suggest that acid rain may be converting a stable form of basic copper sulfate called brochantite, CuSO4 3Cu(OH)2, which formed naturally on the statue's copper surface, into a less stable form of copper sulfate called antlerite, CuSO4 2Cu(OH)2.