The standards selected for Cu were azurite ([Cu.sub.3][(C[O.sub.3]).sub.2][(OH).sub.2]), calcosiderite (Cu,[Fe.sub.6][(P[O.sub.4]).sub.4][(OH).sub.8].4([H.sub.2]O O)), cuprite ([Cu.sub.2]O), libethenite ([Cu.sub.2](P[O.sub.4])(OH)), malachite ([Cu.sub.2](C[O.sub.3])[(OH).sub.2]), nissonite ([Cu.sub.2][Mg.sub.2][(P[O.sub.4]).sub.2][(OH).sub.2].5([H.sub.2]O)), pseudomalachite
([Cu.sub.5][(P[O.sub.4]).sub.2][(OH).sub.4]), tenorite (CuO), and CuS[O.sub.4].
Economic mineralisation in the oxide zone ins primarily malachite, pseudomalachite
and chrysocolla, with heterogenite the main oxide cobalt mineral.
In the Northparkes E22 and E27 deposits at Goonumbla, New South Wales, upper oxidation zones are dominated by libethenite and pseudomalachite
, with azurite and malachite emplacement at greater depths.
Chrysocolla is the predominant mineralisation within the oxide ore, but there is also pseudomalachite
Terry Szenics had some exceptional specimens of well crystallized pseudomalachite
from a new find at the Manto Cuba mine at Inca de Oro, Chile.
These include sicklerite, purpurite, hureaulite, phosphosiderite, strengite, stewartite, eosphorite, robertsite, mitridatite, jahnsite, fairfieldite, hopeite, and pseudomalachite
. Sinkankas (1997) also reports the presence of bismuth-containing minerals including clinobisvanite, namibite, and beyerite.
Associated minerals are: orthoclase, chalcocite, covellite, pseudomalachite
, chalcosiderite/turquoise, ulrichite, libethenite, torbernite and iodargyrite.
Sprays of bright olive-green libethenite crystals were again found but this time tsumebite, pseudomalachite
and pyromorphite were found in addition to plumbogummite and crandallite.
Namibite also has been identified from the Stewart mine, Pala district, with associated chrysocolla and pseudomalachite
Jordi Fabre (in his "fishbowl" booth in the main lobby of the Executive Inn - his flyer shows a swimming fish with Jordi's face on it grinning out from a bowl) kept busy mostly by selling Spanish pyromorphite (next paragraph): but I found interesting, too, the 20 or so miniatures of newly mined pseudomalachite
from Vilavicosa, Estremoz, Portugal.
These are often overlooked in oxidized ores, although pseudomalachite
, [Cu.sub.5][(P[O.sub.4]).sub.2][(OH).sub.4], is a common mineral in Australian oxidized zones.
As a result of the metallurgical problems, X-ray diffraction studies were undertaken back in Cape Town where it was discovered that a principal "oxide" ore, previously described as malachite or pseudomalachite
, was in fact brochantite, an extremely easy mineral to acid-leach but not simple to float.