Chalcopyrite

Chalcopyrite (/kalkoˈpairəit/) is a copper airn sulfide mineral that crystallizes in the tetragonal seestem. It haes the chemical composeetion CuFeS₂. It haes a brassy tae gowden yellae colour an a haurdness o 3.5 tae 4 on the Mohs scale. Its streak is diagnostic as green tinged black.

Chalcopyrite
Twinned chalcopyrite crystal frae the Camp Bird Mine, Ouray Coonty, Colorado. Crystal is aboot 1 cm x 1 cm.
General
Category	Sulfide mineral
Formula (repeatin unit)	CuFeS2
Strunz clessification	02.CB.10a
Creestal seestem	Tetragonal Scalenohedral 42m
Space group	Tetragonal 42m – scalenohedral
Unit cell	a = 5.289 Å, c = 10.423 Å; Z = 4
Identification
Formula mass	183.54
Colour	Brass yellae, mey hae iridescent purplish tarnish.
Creestal habit	Predominantly the disphenoid an resembles a tetrahedron, commonly massive, an whiles botryoidal.
Twinnin	Penetration twins
Cleavage	Indistinct on {011}
Fractur	Irregular tae uneven
Tenacity	Brickle
Mohs scale haurdness	3.5
Skinkle	Metallic
Streak	Greenish black
Diaphaneity	Opaque
Speceefic gravity	4.1 – 4.3
Solubility	Soluble in HNO3
Ither chairacteristics	magnetic on heatin
References

On exposur tae air, chalcopyrite oxidises tae a variety o oxides, hydroxides an sulfates. Associated copper minerals include the sulfides bornite (Cu₅FeS₄), chalcocite (Cu₂S), covellite (CuS), digenite (Cu₉S₅); carbonates lik malachite an azurite, an rarely as oxides lik cuprite (Cu₂O). Chalcopyrite is rarely foond in association wi native copper.