IDAITE

    Class : Sulfides and sulfosalts
    Subclass : Sulfides
    Crystal system : Hexagonal
    Chemistry : Cu3FeS4
    Rarity : Uncommon

Idaite is essentially a secondary mineral of the cementation zone, where it results from the decomposition of bornite. It is also known as a primary sulphide in high temperature deposits, in exsolution in chalcopyrite. Its name comes from its discovery location : the Ida mine (Namibia). Idaite constitutes tiny lamellae resembling covellite as well as small grains, usually carried by bornite. It has a color similar to bornite but unlike the latter does not tarnish in the air. It is accompanied by numerous copper minerals (bornite, chalcopyrite, covellite, digenite, etc...) sometimes by mackinawite (high temperature deposit). It is a very accessory ore of copper.

Main photo : Exsolution of idaite (red) in chalcopyrite from Undu mine, Nukundamu, Vanua Levu, Fiji © Günter Grundmann

Idaite in the World

Although very scarce, idaite is known as a microscopic constituent in many copper deposits, especially at Chañarcillo (Chile), Skouriotissa (Cyprus) and Tsumeb (Namibia).

Idaite in France

In France, idaite is reported in many deposits such as the Clausis copper mine (Hautes-Alpes), Barlet (Haute-Loire), the Chizeuil mine (Saône-et-Loire), Ste- Lucie (Lozère), Rabejac (Hérault), etc...

Twinning

No twins known for this mineral species.

Fakes and treatments

No fakes recorded for this mineral species.


Hardness : 2.5 to 3.5
Density : 4.2
Fracture : Irregular to sub-conchoidal
Streak : -

TP : Opaque
RI : -
Birefringence : -
Optical character : -
Pleochroism : None
Fluorescence : None

Solubility : -

Magnetism : NoneRadioactivity : None