|Chemical formula||copper iron sulfide:CuFeS2|
|Color||Brass yellow, may have iridescent purplish tarnish.|
|Crystal habit||predominantly the disphenoid and resembles a tetrahedron. Crystals sometines twinned. Also commonly massive, and sometimes botryoidal.|
|Crystal system||tetragonal bar 4 2m|
|Fracture||conchoidal and brittle|
|Mohs Scale hardness||3.5|
|Specific gravity||4.1 - 4.3|
|Solubility||Soluble in HNO3|
|Other Characteristics||magnetic on heating|
The name is pronounced kal-co-pie-right (kal as in "calendar", "co" as in coat).
On exposure to air, chalcopyrite oxidises to a variety of oxides, hydroxides and sulfates. Associated copper minerals include the sulfides bornite (Cu5FeS4), chalcocite (Cu2S), covellite (CuS), digenite (Cu9S5); carbonates such as malachite and azurite, and rarely oxides such as cuprite (Cu2O). Chalcopyrite is rarely found in association with native copper.
Chalcopyrite is often confused with pyrite, although the latter has a cubic and not a tetragonal crystal system. Further, chalcopyrite is often massive, rarely crystalline, and less brittle. Chalcopyrite is also a darker yellow in color, with a greenish tinge and diagnostic greasy lustre.
Due to its color and high copper content, chalcopyrite has often been referred to as "yellow copper".
Natural chalcopyrite has no solid solution series with any other sulfide minerals. There is limited substitution of Zn with Cu despite chalcopyrite having the same crystal structure as sphalerite.
However, it is often contaminated by a variety of other trace elements such as Co, Ni, Mn, Zn and Sn substituting for Cu and Fe. Se, Fe and As substitute for sulfur, and trace amounts of Ag, Au, Pt, Pd, Pb, V, Cr, In, Al and Sb are reported.
Chalcopyrite is present within many ore bearing environments via a variety of ore forming processes.
Chalcopyrite is present in volcanogenic massive sulfide ore deposits and sedimentary exhalative deposits, formed by deposition of copper during hydrothermal circulation. Chalcopyrite is concentrated in this environment via fluid transport.
Porphyry copper ore deposits are formed by concentration of copper within a granite stock during the ascent and crystallisation of a magma. Chalcopyrite in this environment is produced by concentration within a magma system.
Chalcopyrite is an accessory mineral in Kambalda type komatiitic nickel ore deposits, formed from an immiscible sulfide liquid in sulfur-saturated ultramafic lavas. In this environment chalcopyrite is formed by a sulfide liquid stripping copper from an immiscible silicate liquid.
Chalcopyrite is the most important copper ore. Chalcopyrite ore occurs in a variety of ore types, from huge masses as at Timmins, Ontario, to irregular veins and disseminations associated with granitic to dioritic intrusives as in the porphyry copper deposits of Broken Hill, the American cordillera and the Andes.
Chalcopyrite may also be found in coal seams associated with pyrite nodules, and as disseminations in carbonate sedimentary rocks.
bg:Халкопирит ca:Calcopirita cs:Chalkopyrit de:Chalkopyrit gl:Calcopirita it:Calcopirite he:כלקופיריט lt:Chalkopiritas jbo:kalkopairait hu:Kalkopirit nl:Chalcopyriet no:Kopperkis nn:Koparkis nds:Chalkopyrit simple:Chalcopyrite sk:Chalkopyrit fi:Kuparikiisu sv:Kopparkis uk:Халькопірит