Delafossite - Encyclopedia
Class : Oxides et hydroxides
Subclass : Oxides
Crystal system : Trigonal
Chemistry : CuFeO2
Rarity : Rare
Delafossite is a rare oxide of copper and iron. It is essentially a secondary mineral from the oxidation zone of copper deposits which is associated with other secondary copper or iron minerals (cuprite, hematite, tenorite, malachite, etc...). It was named in honor of the French mineralogist and crystallographer Gabriel Delafosse. Delafossite forms small tabular to equant crystals (up to 8 mm), botryoidal crusts, spherolites or powdery masses, black in color.
Main photo : Delafossite from Gosenbach, Siegen, Germany © Matthias Reinhardt
Delafossite in the World
Twinning
No twin known for this mineral species.
Fakes and treatments
No fakes listed for this mineral species.
Hardness : 5.5
Density : 5.41
Fracture : Undetermined
Streak : Black
TP : Opaque
RI : -
Birefringence : -
Optical character : -
Pleochroism : None
Fluorescence : None
Solubility : Sulfuric acid and hydrochloric acid
Magnetism : Paramagnetic
Radioactivity : None