What is chalchpyrite?

Chalcopyrite is CuFeS₂. It has brass yellow or golden yellow colour.

Approved

Chalcopyrite  is a copper iron sulfide mineral that crystallizes in the tetragonal system. It has the chemical composition CuFeS₂. It has a brassy to golden yellow color and a hardness of 3.5 to 4 on the Mohs scale. Its streak is diagnostic as green tinged black.

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.

Twinned chacopyrite crystal from the Camp Bird Mine, Ouray County, Colorado (size:5.2 x 3.6 x 2.7 cm)
General
Category	Sulfide mineral
Chemical formula	CuFeS2
Strunz classification	02.CB.10a
Crystal symmetry	Tetragonal 42m – scalenohedral
Unit cell	a = 5.289 Å, c = 10.423 Å; Z = 4
Identification
Molar mass	183.54
Color	Brass yellow, may have iridescent purplish tarnish.
Crystal habit	Predominantly the disphenoid and resembles a tetrahedron, commonly massive, and sometimes botryoidal.
Crystal system	Tetragonal Scalenohedral 42m
Twinning	Penetration twins
Cleavage	Indistinct on {011}
Fracture	Irregular to uneven
Tenacity	Brittle
Mohs scale hardness	3.5
Luster	Metallic
Streak	Greenish black
Diaphaneity	Opaque
Specific gravity	4.1 – 4.3
Solubility	Soluble in HNO3
Other characteristics	magnetic on heating

The unit cell of chalcopyrite. Copper is shown in pink, iron in blue and sulfur in yellow.

APPROVE IF U LIKE...

Approved