Idaite - Encyclopedia
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
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