Chalcopyrite "Blister Copper", Botroïdale form (7x4.3cm) Locality : Redruth Cornwall England — Photo: Didier Descouens · CC BY-SA 3.0
Chalcopyrite
Also known as: Copper pyrites, Peacock ore (when tarnished).
Copper-iron sulfide — the single most important copper ore on Earth, brassy yellow and often iridescent when tarnished.
Intro adapted from Wikipedia (CC BY-SA).
Chalcopyrite is an IMA-recognized mineral species in the sulfide class, with the chemical formula CuFeS₂.
It crystallizes in the tetragonal crystal system (space group I-42d). It is a member of the Chalcopyrite structural group.
Key properties: Mohs hardness 3.5–4; specific gravity 4.1–4.3; typically yellow or orange; Greenish black streak; Metallic. Anisotropism: Weak. R1 –R2: (400) 16.0–17.3, (420) 20.0–21.3, (440) 24.8–26.1, (460) 30.2–31.4 luster.
IMA symbol Ccp, grandfathered status — known before the IMA’s founding, named in 1725.
Found as a primary mineral in hydrothermal veins, stockworks, disseminations, and massive replacements; an exsolution product in mafic igneous rocks; of sedimentary origin controlled by redox conditions.
It is found associated with Sphalerite, galena, tetrahedrite, pyrite, many copper sulfides.
Its name comes from the Greek for brass and pyrite.
Collections: Metals & Native Elements, Collector Favorites.