(n.) A valuable ore of copper, containing copper, iron, and sulphur; -- also called purple copper ore (or erubescite), in allusion to the colors shown upon the slightly tarnished surface.
Example Sentences:
Covellite
Definition:
(n.) A native sulphide of copper, occuring in masses of a dark blue color; -- hence called indigo copper.
Example Sentences:
(1) Optimum conditions for the oxidation of chalcocite were: pH, 1.7 to 2.3; temperature, 35 C; and ferric iron concentration in the range of 0.004 to 0.01 M. For covellite, the optimum conditions were: pH 2.3; temperature, 35 C; and ferric iron concentration in the range of 0.004 to 0.02 M. The energies of activation were determined to be 16.3 kcal (ca.
(2) Biodegradation of chalcocite was found to be 90 to 100% and that of covellite 45 to 60%.
(3) "Oxygraph" apparatus was used to measure quantitatively the kinetics of oxidation of synthetic covellite (CuS) in the presence and absence of Thiobacillus species.
(4) In contrast, all Cu X-ray photoelectron signals of the more tentatively described mixed valence complexes Na2Cu3S3 and the mineral covellite, CuI4CuII2(S2)2S2, could be attributed exclusively to Cu(I).
(5) 4.8 X 10(4) J) per mol for chalcocite and covellite, respectively.
(6) The microbiological oxidation of synthetic chalcocite and covellite has been investigated using an adapted strain of Thiobacillus ferrooxidans.