Chalcopyrite - Definition and Overview

Chalcopyrite
Chalcopyrite
General
Category	Mineral
Chemical formula	copper iron sulfide:CuFeS2
Identification
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
Cleavage	[112] Indistinct
Fracture	conchoidal and brittle
Mohs Scale hardness	3.5
Luster	metallic
Refractive index	opaque
Pleochroism	N/A
Streak	dark green
Specific gravity	4.1 - 4.3
Fusibility	2
Solubility	?
Other Characteristics	magnetic on heating
Major varieties

Chalcopyrite is a copper iron sulfide mineral that crystallizes in the tetragonal system. It has chemical composition CuFeS₂. It has a brassy to golden yellow color and hardness of 3.5 to 4 on the Mohs scale. Due to its color it is often confused with pyrite though this mineral has a cubic and not a tetragonal crystal system and chalcopyrite is more often massive and less brittle. Chalcopyrite is also a darker yellow in color.

Chalcopyrite is one of the most important copper ores. 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 the American cordillera and the Andes.

References

• Dana's Manual of Mineralogy ISBN 0471032883
• mindat.org (http://www.mindat.org/min-955.html)
• Webmineral.com (http://webmineral.com/data/Chalcopyrite.shtml)
• Mineral Galleries (http://mineral.galleries.com/minerals/sulfides/chalcopy/chalcopy.htm)