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Topic: Chalcocite

	chalcocite.htm
		Description: Chalcocite is formed either as a primary vein mineral or, more typically, in supergene deposits where it forms as a result of the redeposition of copper from the breakdown of minerals such as chalcopyrite or bornite.
		Chalcocite is distinguished with difficulty from digenite (Cu9S5) and djurleite (Cu31S16), both of which may form by the leaching of chalcocite.
		CRAWFORD COUNTY: Chalcocite is one of the components of the ore at the Plum Creek copper mine in the SE SW Sec.
	www.uwrf.edu /~william.s.cordua/chalcocite.htm (0 words)

	Chalcocite - Biocrawler (Site not responding. Last check: 2007-10-31)
		Chalcocite is sometimes found as a primary vein mineral in hydrothermal veins.
		Since chalcocite is a secondary mineral that forms from the alteration of other minerals, it has been known to form pseudomorphs of many different minerals.
		Chalcocite has been known to form pseudomorphs of the minerals bornite, covellite, chalcopyrite, pyrite, enargite, millerite, galena and sphalerite.
	www.biocrawler.com /encyclopedia/Chalcocite (304 words)

	CHALCOCITE (Copper Sulfide)
		Chalcocite is an important copper mineral ore. It has been mined for centuries and is one of the most profitable copper ores.
		Since chalcocite is a secondary mineral that forms from the alteration of other minerals, it has been known to form pseudomorphs of many different minerals.
		Chalcocite has been known to form pseudomorphs of the minerals bornite, covellite, chalcopyrite, pyrite, enargite, millerite, galena and sphalerite.
	mineral.galleries.com /minerals/sulfides/chalcoci/chalcoci.htm (0 words)

	Rocks and Minerals Tour: Envi Sci Dept, UVA
		Chalcocite is an opaque mineral that is dark lead-gray, sometimes fl, with a metallic luster.
		Chalcocite is important as a source of copper because of its high copper concentration, about 80% by weight, and the ease with which it can be separated from sulfur.
		Chalcocite is not, however, the primary source of copper due to its scarcity.
	www.evsc.virginia.edu /tours/rockmin/chalcocite.shtml (194 words)

	Butte ores
		The Butte, Montana copper ores illustrate typical replacement textures: 1) irregularly shaped replacement remnants ("sea islands") of pyrite being replaced by chalcocite, 2) caries texture in which chalcocite embayments into pyrite are concave with respect to the host pyrite, and 3) vein texture in which chalcocite replacement veins traverse pyrite.
		Each of the replacements are shown by the presence of irregularly shape inclusions (sea islands) of the earlier mineral engulfed by the later mineral, and by the local presence of caries and vein textures.
		Although part of the white material marked Cc is chalcocite, much of it is covellite with an orientation that gives it a color and reflectance that nearly matches that of chalcocite.
	web.umr.edu /~rhagni/butteores.html (0 words)

	Minerals of the Cu-S system from the Logatchev field (Mid-Atlantic Ridge)
		It was concluded that the hexagonal chalcocite was primary formed from high temperature fluids and it was substituted by the non-stoichiometric copper sulfides in succession: djurleite-anilite-geerite-spioncopite-yarrowite.
		Chalcocite and digenite, noted in published papers, were also indentified: the former as relicts only, the latter as a component of the digenite-bornite solid solutions.Two ranges of copper sulfides (chalcocite-digenite and geerite-covellite) were recognized on the base of their compositions, pecularities of aggregates and distribution.
		The first one (chalcopyrite - bornite - bornite-digenite solid solution - chalcocite) is proposed to be connected with activity of ascending termal fluids, the second one (djurleite - anilite - geerite - spionkopite - yarrowite - covellite) is a result of hypergenetic transformations of massive sulfides due to action of surrounding sea water.
	www.igem.ru /igem/mine/logatchev.htm (1295 words)

	In Memoriam—The Flambeau Mine, Rusk County, Wisconsin June 1993-March 1997 Rocks & Minerals - Find Articles (Site not responding. Last check: 2007-10-31)
		Of interest to the mineral collector are the hundreds of superb groups of chalcocite crystals that were recovered from the mining operation by Casey Jones of Burminco, who had an exclusive specimen recovery contract with Flambeau Mining Company.
		The largest group of chalcocite crystals recovered, which measures 20 by 24 cm, was acquired by the A. Seaman Mineral Museum, Michigan Technological University, and is now on display with other specimens from the mine.
		Chalcocite, [Cu.sub.2]S, is the main ore of copper in the deposit and has made the mine famous worldwide for the superb groups of crystals that have been recovered.
	findarticles.com /p/articles/mi_m0GDX/is_1997_Sept/ai_53288908 (847 words)

	USGS Professional Paper 144 pp 141-146
		Chalcocite is invariably associated with the native copper, which it apparently follows in age.
		At Meriden a core of native copper is inclosed by a shell of chalcocite, thus indicating the chalcocite to be the younger mineral.
		Copper sulphide, principally chalcocite, has replaced dolomite underlying basalt, and chalcopyrite and chalcocite are disseminated in some of the sills or dikes of the region.
	www.minsocam.org /msa/collectors_corner/usgs/pp144_pp_141_146.htm (4197 words)

	In Memoriam—The Flambeau Mine, Rusk County, Wisconsin June 1993-March 1997 Rocks & Minerals - Find Articles (Site not responding. Last check: 2007-10-31)
		Of interest to the mineral collector are the hundreds of superb groups of chalcocite crystals that were recovered from the mining operation by Casey Jones of Burminco, who had an exclusive specimen recovery contract with Flambeau Mining Company.
		The largest group of chalcocite crystals recovered, which measures 20 by 24 cm, was acquired by the A. Seaman Mineral Museum, Michigan Technological University, and is now on display with other specimens from the mine.
		Chalcocite, [Cu.sub.2]S, is the main ore of copper in the deposit and has made the mine famous worldwide for the superb groups of crystals that have been recovered.
	www.findarticles.com /p/articles/mi_m0GDX/is_1997_Sept/ai_53288908 (847 words)

	SKB report on copper corrosion 1995
		However, the conditions for growth of chalcocite nucleus on the copper surface, which depends on the surface energies, should be investigated in order to cancel the possibility of whiskers formation.
		C chalcocite precipitated on the copper surface may be of β-phase due to influence from the copper metal lattice.
		The crystal lattice of the copper metal may have an influence of the phase of the chalcocite only if the chalcocite is precipitated as a layer on the copper surface and the chalcocite will transform to γ-phase when it grows out from the surface.
	www.lwr.kth.se /Personal/personer/levlin_erik/SKBrep95.htm (2230 words)

	NMBGMR Circular 112 (Site not responding. Last check: 2007-10-31)
		Although the dissolution of chalcocite in a variety of lixivants has been studied by many investigators, none has completely defined the chemistry and mechanism of chalcocite dissolution, and in particular, the mechanism of dissolution in oxygenated acid solution has not been resolved.
		The importance of chalcocite as an ore mineral in copper leach dumps justifies a detailed study of its dissolution in oxygenated acid solution.
		This study is to determine the reaction for the dissolution of chalcocite in oxygenated sulfuric acid solution, establish a general rate equation for this reaction, and describe a mechanism of chalcocite dissolution, based on a combination of thermodynamic, chemical, kinetic, and physical studies.
	geoinfo.nmt.edu /publications/circulars/112/home.html (0 words)

	reportonbusiness.com: globeinvestor.com
		Significant copper oxide and sulfide mineralization, including bornite, chalcopyrite and chalcocite, were intersected in 5 of the 7 holes.
		Chalcocite in potentially significant amounts was observed in drill holes WP-2 and WP-4.
		Chalcopyrite, chalcocite, molybdenite, cuprite and native copper were observed in one or more of the other four holes in at least minor quantities.
	www.globeinvestor.com /servlet/WireFeedRedirect?cf=GlobeInvestor/config&vg=BigAdVariableGenerator&date=20041026&archive=ccnm&slug=1026078n (1148 words)

	Presidental Address Bowen
		In the joint investigation the group of geologists reexamined the evidence, greatly extended existing knowledge of the ores, and were able to make additional suggestions as to the probable character of the processes whereby secondary enrichment is accomplished.
		The group of chemists studied the relations of the sulphides to each other, established the variable chemical composition of chalcocite, the fl sulphide which is frequently formed during secondary enrichment, and determined the effect of composition upon the inversion temperature from the orthorhombic to the higher-temperature, isometric form.
		Although chalcocite of isometric outward form has not been found in nature, some massive examples of the mineral show an octahedral etch pattern which, if the excess sulphur is less than 8 per cent, proves their formation above 91°.
	www.minsocam.org /msa/collectors_corner/arc/bowenpa.htm (2489 words)

	Amazon.com: chalcocite: Books (Site not responding. Last check: 2007-10-31)
		Analysis of the oxidation of chalcopyrite, chalcocite, galena, pyrrhotite, marcasite, and arsenopyrite (SuDoc I 28.23:9118) by G. Reimers (Unknown Binding - 1987)
		The relation of bornite and chalcocite in the copper ores of the Virginia district of North Carolina and Virginia by Francis Baker Laney (Unknown Binding - 1911)
		CHALCOCITE Cu2S Orthorhombic Almost 80% copper, chalcocite is the penulti- mate...
	www.amazon.com /s?ie=UTF8&keywords=chalcocite&index=books&page=1 (1036 words)

	FM-TGMS-MSA Symposium on Copper and Copper Minerals: Introduction Mineralogical Record - Find Articles
		Chalcocite crystals produced by supergene enrichment of a CuZn-Au massive sulfide deposit in the Flambeau mine rank among the best in the world.
		Inward from the cellular margin are skeletal chalcocite crystals, or crystals with curved or rounded faces, which are overgrown by partial crystals * ith moderately well-developed faces.
		As the water table rose, the chalcocite crystals were covered with deeper levels of groundwater, in which bornite is the stable copper mineral, and a thin coating of bornite was deposited on the earlier chalcocite crystals.
	findarticles.com /p/articles/mi_qa3672/is_199701/ai_n8740555/pg_3 (595 words)

	Garvin County, Paoli Brochantite & Copper Minerals
		Near the bottom of the sandstone bed were long, thin stringers of a dark material primarily composed of chalcocite, with some cuprite.
		Malachite is widespread in the Paoli district as alterations of chalcocite nodules and as cement and intergrowths with sandstone.
		Microscopic examination of several of the brochantite specimens reveals a brilliant blue crystallized material associated with cuprite, brochantite and chalcocite; crystals are generally about 0.1 mm in maximum dimension.
	www.brightok.net /~rockman/PaoliBro/PaoliBro.htm (1790 words)

	Keweenaw Michigan field trip
		Cliff mine mineralogy – adularia, albite, analcime, azurite, babingtonite, barite, calcite, chalcocite, chamosite, chrysocolla, copper, covellite, cuprite, datolite, epidote, fluorapophyllite, galena, gypsum, hematite, laumontite, microcline, natrolite, prehnite, pumpellyite, pyrite, quartz, silver, sphalerite, tenorite, thomsonite.
		Mineralogy of the conglomerate lodes – barite, calcite, chalcocite, chrysocolla, copper, cuprite, epidote, laumontite, malachite, microcline, orthoclase, powellite, pumpellyite, quartz, silver, and tenorite.
		Vein minerals - barite, bastnaesite, bismuth, bornite, calcite, calumenite, chalcocite, chalconatronite, chalcopyrite, chlorite, copper, covellite, cuprite, dolomite, domeykite, galena, greenockite, graphite, illite, malachite, microcline, montmorillonite, molybdenite, pyrite, quartz, silver, sphalerite, synchysite.
	www.minsocam.org /MSA/collectors_corner/vft/mi4b.htm (456 words)

	Chalcocite
		It was first brought to the author’s attention in 1909 by Mr.
		McGovern, of Franklin, who sent a specimen for determination, showing a thin calcite vein containing granular sphalerite and galena, with a few imperfect crystals of chalcocite.
		Later in the same year was made the interesting discovery of massive chalcocite associated with silver and magnetite, described under silver.
	franklin-sterlinghill.com /palache/chalcocite.stm (59 words)

	AZCO Mining, Inc - Exploration - Acquisition - Technology
		Oxidation of primary and secondary sulfides generated chalcocite, chrysocolla, neotocite/tenorite, limonite copper mineralization, cuprite, native copper, and accessory malachite, brochantite, libethenite, and azurite.
		Chalcocite enrichment was developed in the more pyritic quartz-sericite alteration and copper oxides were formed in the central weak potassic and biotite stable zones.
		The highest IP responses on sections with known chalcocite mineralization, 698,200E and 697,600E, do not coincide with the best copper mineralization, but are displaced to the south where it is known from drilling that a late-stage pyritic quartz-feldspar porphyry has overprinted the porphyry system.
	www.azco.com /investors/press/press2.php (3103 words)

	Activity 22: Covellite or Chalcocite ??? - Maine Geological Survey
		The mineral chalcocite, also a major ore of copper, has the formula Cu Chalcocite was mined in Roman times in the area of England now known as Cornwall.
		While a number of more complex models for the laboratory production of these minerals exists, the basic technique is to heat a given amount of copper, in combination with excess sulfur in a closed crucible under a fume hood.
		Chalcocite - Cu S 2Cu + S ------> Cu 0.50 g Cu x (1 mole Cu / 63.54 g/mole) = 0.008 moles Cu 0.008 moles Cu x (1 mole Cu S / 2 mole Cu) x (159.08 g Cu S / 1 mole Cu S) = 0.636 g Cu Student Sheet
	www.maine.gov /doc/nrimc/mgs/education/lessons/act22.htm (0 words)

	McGraw-Hill AccessScience: Bornite (Site not responding. Last check: 2007-10-31)
		The metallic and brassy color of a fresh surface rapidly tarnishes upon exposure to air to a characteristic iridescent purple, giving rise to the name "peacock ore." Bornite exhibits considerable solid solution at elevated temperatures.
		Upon cooling, other copper sulfides, such as chalcopyrite, chalcocite, and digenite, may be exsolved.
		Though of lesser importance as an ore than chalcocite or chalcopyrite, masses of bornite have been mined in Chile, Peru, Bolivia, and Mexico and in the United States in Arizona and Montana.
	www.accessscience.com /Encyclopedia/0/09/Est_091800_frameset.html?doi (185 words)

	PRESS RELEASE Philex Gold Announces Results of Infill Drill Holes at the Boyongan Property for the First Quarter of 2007 (Site not responding. Last check: 2007-10-31)
		The base of oxidation was noted at 394m depth and supergene mineralisation comprises limonite, neoticite, pitch limonite, cuprite, azurite, malachite and chalcocite.
		The base of oxidation was noted at 335m depth and supergene mineralisation comprises limonite, cuprite, native copper and chalcocite.
		The base of oxidation was noted at 401m depth and supergene mineralisation comprises limonite, cuprite, native copper and chalcocite.
	www.marketwire.com /mw/release_html_b1?release_id=248986 (1994 words)

	Chalcocite Oxidation and Coupled Carbon Dioxide Fixation by Thiobacillus ferrooxidans -- Nielsen and Beck 175 (4026): ...
		Chalcocite Oxidation and Coupled Carbon Dioxide Fixation by Thiobacillus ferrooxidans -- Nielsen and Beck 175 (4026): 1124 -- Science
		Chalcocite Oxidation and Coupled Carbon Dioxide Fixation by Thiobacillus ferrooxidans
		provided by the oxidation of the cuprous copper of the chalcocite.
	www.sciencemag.org /cgi/content/short/175/4026/1124 (0 words)

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