Bornite has a brown to copper-red color on fresh surfaces that tarnishes to various iridescent shades of blue to purple in places. Its striking iridescence gives it the nickname peacock copper or peacock ore.
At temperatures above 228 °C (442 °F), the structure is isometric with a unit cell that is about 5.50 Å on an edge. This structure is based on cubic close-packed sulfur atoms, with copper and iron atoms randomly distributed into six of the eight tetrahedral sites located in the octants of the cube. With cooling, the Fe and Cu become ordered, so that 5.5 Å subcells in which all eight tetrahedral sites are filled alternate with subcells in which only four of the tetrahedral sites are filled; symmetry is reduced to orthorhombic.[5]
Compositionedit
Substantial variation in the relative amounts of copper and iron is possible and solid solution extends towards chalcopyrite (CuFeS2) and digenite (Cu9S5). Exsolution of blebs and lamellae of chalcopyrite, digenite, and chalcocite is common.[5]
Bornite with silver from Zacatecas, Mexico (size: 7.5 × 4.3 × 3.4 cm)
It occurs globally in copper ores with notable crystal localities in Butte, Montana and at Bristol, Connecticut in the U.S. It is also collected from the Carn Brea mine, Illogan, and elsewhere in Cornwall, England. Large crystals are found from the Frossnitz Alps, eastern Tirol, Austria; the Mangula mine, Lomagundi district, Zimbabwe; from the N'ouva mine, Talate, Morocco, the West Coast of Tasmania and in Dzhezkazgan, Kazakhstan.[3] There are also traces of it found amongst the hematite in the Pilbara region of Western Australia.
^ abBarthelmy, David (2014). "Bornite Mineral Data". Webmineral.com. Retrieved 12 August 2022.
^ abcAnthony, John W.; Bideaux, Richard A.; Bladh, Kenneth W.; Nichols, Monte C. (2005). "Bornite" (PDF). Handbook of Mineralogy. Mineral Data Publishing. Retrieved 12 August 2022.
^ abcNesse, William D., "Sulfides and Related Minerals" in Introduction to Mineralogy, New York: Oxford University Press, 2000, p 429
Bibliographyedit
Palache, C., H. Berman, and C. Frondel (1944) Dana’s system of mineralogy, (7th edition), v. I, 195–197.
Manning, P.G. (1966) A study of the bonding Properties of Sulphur in Bornite, The Canadian Mineralogist, 9, 85-94
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Look up bornite in Wiktionary, the free dictionary.
February 15, 2024
bornite, also, known, peacock, sulfide, mineral, with, chemical, composition, cu5fes4, that, crystallizes, orthorhombic, system, pseudo, cubic, lightly, iridescent, bornite, crystal, quartz, needles, from, kazakhstanspecimen, size, generalcategorysulfide, mine. Bornite also known as peacock ore is a sulfide mineral with chemical composition Cu5FeS4 that crystallizes in the orthorhombic system pseudo cubic BorniteLightly iridescent bornite crystal on quartz needles from KazakhstanSpecimen size 3 6 cm 2 2 cm 1 2 cm 1 42 in 0 87 in 0 47 in GeneralCategorySulfide mineralFormula repeating unit Cu5FeS4IMA symbolBn 1 Strunz classification2 BA 10Crystal systemOrthorhombicCrystal classDipyramidal mmm H M symbol 2 m 2 m 2 m Space groupPbcaUnit cella 10 95 A b 21 862 A c 10 95 A Z 16IdentificationFormula mass501 88 g molColorCopper red bronze brown purpleCrystal habitGranular massive disseminated Crystals pseudocubic dodecahedral octahedralTwinningPenetration twins on 111 CleavagePoor on 111 FractureUneven to subconchoidalTenacityBrittleMohs scale hardness3 3 25LusterMetallic if fresh iridescent tarnishStreakGrayish blackSpecific gravity5 06 5 08Refractive indexOpaquePleochroismWeak but noticeableOther characteristicsMagnetic after heating iridescentReferences 2 3 4 Contents 1 Appearance 2 Mineralogy 2 1 Structure 2 2 Composition 2 3 Form and twinning 3 Occurrence 4 History and etymology 5 See also 6 References 7 BibliographyAppearance edit nbsp Tarnish of borniteBornite has a brown to copper red color on fresh surfaces that tarnishes to various iridescent shades of blue to purple in places Its striking iridescence gives it the nickname peacock copper or peacock ore Mineralogy editBornite is an important copper ore mineral and occurs widely in porphyry copper deposits along with the more common chalcopyrite Chalcopyrite and bornite are both typically replaced by chalcocite and covellite in the supergene enrichment zone of copper deposits Bornite is also found as disseminations in mafic igneous rocks in contact metamorphic skarn deposits in pegmatites and in sedimentary cupriferous shales 3 It is important as an ore for its copper content of about 63 percent by mass 2 Structure edit nbsp Microscopic picture of BorniteAt temperatures above 228 C 442 F the structure is isometric with a unit cell that is about 5 50 A on an edge This structure is based on cubic close packed sulfur atoms with copper and iron atoms randomly distributed into six of the eight tetrahedral sites located in the octants of the cube With cooling the Fe and Cu become ordered so that 5 5 A subcells in which all eight tetrahedral sites are filled alternate with subcells in which only four of the tetrahedral sites are filled symmetry is reduced to orthorhombic 5 Composition edit Substantial variation in the relative amounts of copper and iron is possible and solid solution extends towards chalcopyrite CuFeS2 and digenite Cu9S5 Exsolution of blebs and lamellae of chalcopyrite digenite and chalcocite is common 5 Form and twinning edit Rare crystals are approximately cubic dodecahedral or octahedral Usually massive Penetration twinning on the crystallographic direction 111 5 Occurrence edit nbsp Bornite with silver from Zacatecas Mexico size 7 5 4 3 3 4 cm It occurs globally in copper ores with notable crystal localities in Butte Montana and at Bristol Connecticut in the U S It is also collected from the Carn Brea mine Illogan and elsewhere in Cornwall England Large crystals are found from the Frossnitz Alps eastern Tirol Austria the Mangula mine Lomagundi district Zimbabwe from the N ouva mine Talate Morocco the West Coast of Tasmania and in Dzhezkazgan Kazakhstan 3 There are also traces of it found amongst the hematite in the Pilbara region of Western Australia History and etymology editIt was first described in 1725 for an occurrence in the Ore Mountains Bohemia in what is now the Karlovy Vary Region of the Czech Republic It was named in 1845 for Austrian mineralogist Ignaz von Born 4 See also editCuprite Tennantite Tetrahedrite List of minerals named after peopleReferences edit Warr L N 2021 IMA CNMNC approved mineral symbols Mineralogical Magazine 85 3 291 320 Bibcode 2021MinM 85 291W doi 10 1180 mgm 2021 43 S2CID 235729616 a b Barthelmy David 2014 Bornite Mineral Data Webmineral com Retrieved 12 August 2022 a b c Anthony John W Bideaux Richard A Bladh Kenneth W Nichols Monte C 2005 Bornite PDF Handbook of Mineralogy Mineral Data Publishing Retrieved 12 August 2022 a b Bornite Mindat org retrieved 12 August 2022 a b c Nesse William D Sulfides and Related Minerals in Introduction to Mineralogy New York Oxford University Press 2000 p 429Bibliography editPalache C H Berman and C Frondel 1944 Dana s system of mineralogy 7th edition v I 195 197 Manning P G 1966 A study of the bonding Properties of Sulphur in Bornite The Canadian Mineralogist 9 85 94 nbsp Wikimedia Commons has media related to Bornite nbsp Look up bornite in Wiktionary the free dictionary Retrieved from https en wikipedia org w index php title Bornite amp oldid 1195276530, wikipedia, wiki, book, books, library,
