Phase 2: Stronger and later overprinting mineralization events are also evident in most of the new drill holes, including widespread garnet-bearing skarns containing clots, veins, and disseminations of covellite
, native copper, and bornite, with local formation of secondary chalcocite.
Several additional surface-reaching minerals were identified that did not contribute to the golden sheen: pyrite, baryte, covellite
, zircon, muscovite, albite and K-feldspar.
Combined degradation of covellite
by Thiobacillus thiooxidans and Thiobacillus ferrooxidans.
Medium to robust locally bornite, covellite
and pyrite mineralization was seen from 461.
The mineralogy of the Copper lodes consists of chalcopyrite, pyrite, chalcocite, covellite
Mechanisms of bacterial oxidation of the copper sulphide mineral, covellite
, cuprite and native copper were found in the supergene zone.
Other minerals present in the upper zone include bornite, covellite
, chalcocite, prousite, hematite, kaolin, and illite-smectite.
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.
Direct and indirect mechanisms in the bacterial leaching of covellite
This yields an environmentally benign solid leach residue, in the form of covellite
, for pyrometallurgical treatment.