Chalcopyrite

Real mineral · common · CuFeS₂

The most important copper ore mineral. Its iridescent surface tarnish results from oxidation producing thin interference films. Despite its golden colour, it is far softer than pyrite and easily distinguished by its greenish-black streak.

Identity

Formula

CuFeS₂

Chemical class

sulfide

Also known as

Copper pyrite, Peacock ore (tarnished iridescent variety)

Crystallography

Crystal system

tetragonal

Habits

massive, tabular, pyramidal

Fracture

conchoidal

Physical properties

Mohs hardness

3.5

Density

4.2 g/cm³

Luster

metallic

Colors

brass-yellow, metallic yellow, multicolored

Streak

black

Transparency

opaque

Geology

Origins

hydrothermal, igneous

Host rocks

porphyry, granite, basalt

Associated minerals

Pyrite, Sphalerite, Galena, Quartz

Geography

worldwide

Classification

Rarity

common

Gem quality

No

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