Bornite


Also found in: Dictionary, Thesaurus, Wikipedia.
Related to Bornite: chalcocite, Enargite, covellite

bornite

[′bȯr‚nīt]
(mineralogy)
Cu5FeS4 A primary mineral in many copper ore deposits; specific gravity 5.07; the metallic and brassy color of a fresh surface rapidly tarnishes upon exposure to air to an iridescent purple.

Bornite

 

(named after the Austrian metallurgist and mineralogist I. Born, 1742–91), a mottled copper ore, a mineral and a sulfide of copper and iron corresponding to the formula CusFeS4. It contains 52–65 percent copper and 8–12 percent iron. It crystallizes into a cubic system; a modification of a rhombic system is known. Its crystalline structure is of the spinel type. Crystals (cubic or dodecahedral habits) are rare; dense grainy masses are common. They are dark colored, copper red, usually with bright mottled oxide tint in old fractures. Its hardness on the mineralogical scale is 3, and its density is 4,900–5,300 kg/m3.

Bornite is of varying origin. As a hypogene mineral, it is formed in various types of hypothermal deposits. During supergene processes, it is formed in the zone of secondary sulfide concentration. Evolutions of supergene bornite are found in sedimentary rocks, sometimes in the form of pseudomorphoses by organic residues. In hydrothermal deposits, bornite usually is found in association with chalcopy-rite, pyrite, sphalerite, and fahlerz (gray copper ore). It is observed rather frequently in deposits of the type of pyrite seams. Malachite, azurite, cuprite, and other minerals are formed from bornite in oxidation zones. Bornite is an important mineral of copper ores. Deposits of bornite in the USSR are found in the Urals, in the Caucasus, and in Kazakhstan; they are found abroad in the USA, Yugoslavia, South West Africa, and the German Democratic Republic.

References in periodicals archive ?
In the eastern part of the region, where mineral exploration is ongoing in the Ambler Mining District, rigs at Bornite were staffed 100 percent with shareholders.
The 77-million-lb contained cobalt inferred resource at Bornite is one of the largest cobalt resources in North America.
It is interesting to note that the [delta][sup.65]Cu range of high-temperature hypogene chalcocite directly overlaps the 0 [+ or -] 1 [per thousand] range in [delta][sup.65] Cu that has been documented in other copper-rich sulfide minerals (bornite, chalcopyrite) from high-temperature hypogene mineralization, as compiled by Wall et al.
Also, the southern deposits are more polymetallic in composition, including such minerals as galena, sphalerite, pyrite, siderite, chalcopyrite, marcasite, bornite, and quartz.
Minerals associated with cubic magnetite at Balmat, New York Anhydrite [CaSO.sub.4] Arsenopyrite FeAsS Atacamite [Cu.sub.2][Cl(OH).sub.3] Betekhtinite [Cu.sub.10](Pb,Fe)[S.sub.6] Bornite [Cu.sub.5][FeS.sub.4] Bottallackite [Cu.sub.2]Cl[(OH).sub.3] Calcite [CaCO.sub.3] Celestine [SrSO.sub.4] Chalcocite [Cu.sub.2]S Chalcopyrite [CuFeS.sub.2] Digenite [Cu.sub.9][S.sub.5] Galena PbS Gordaite [NaZn.sub.4]([SO.sub.4])[(OH).sub.6]Cl*6[H.sub.2]O Halite NaCl Hematite [Fe.sub.2][O.sub.3] Malachite [Cu.sub.2]([CO.sub.3])[(OH).sub.2] Nantokite CuCl Namuwite [(Zn,Cu).sub.4][SO.sub.4][(OH).sub.6]*4[H.sub.2]O Paratacamite [Cu.sub.2]Cl[(OH).sub.3] Pyrite [FeS.sub.2] Silver Ag Sphalerite ZnS Talc [Mg.sub.3][Si.sub.4][O.sub.10][(OH).sub.2] Crystal Sizes
Mineralization consists not only of disseminated and banded massive sulphides, but also of vein style polymetallic occurrences consisting of pyrite, sphalerite, galena, chalcopyrite, tetrahedrite, argentite, electrum, bornite and ruby silver.
"We believe that there are approximately 77 million pounds of cobalt at our Bornite site, which, if mined, would be the oniy project producing cobalt in the United States," he continues.
"Meanwhile, we will continue to explore our Bornite project in the Ambler district, with a $10 million program funded by South32, which we hope to advance toward a development decision."
The main U minerals at the Olympic Dam are coffinite, brannerite, and uraninite-pitchblende, with minor to trace amounts of U hosted in hematite, thorite-uranothorite, thorianite, crandallite, xenotime-(Y), zircon, REE-group minerals, pyrite, chalcopyrite, bornite, and chalcocite [36].
At Red Dome, the gold is restricted to the skarns and in the primary state occurs as very fine free gold, either as inclusions in sulphides (bornite, chalcocite, chalcopyrite and arsenopyrite), associated with silicates, tellurides and as minor electrum, with free gold in the oxide zone.
Mineralized zones in the porphyry deposits always has lower resistivity and higher chargeability than wall rocks because these deposits have high values of sulfidic minerals such as pyrite, chalcopyrite, chalcocite, covelite and bornite [5,3].