Briartite is an opaque iron-grey metallic sulfide mineral, Cu2(Zn, Fe)GeS4 with traces of Ga and Sn, found inclusions in other germanium-gallium-bearing sulfides. It is a mineral is basically composed of various elements in varying proportions. The molecular weight of Briartite is 390.97.
It was discovered at the Prince Léopold Mine, Kipushi, Shaba, Congo (Léopoldville) in 1965 by Francotte and others, and named for Gaston Briart who had studied formations at Kipushi.
Briartite is also found in Namibia, Greece, and Spain.
- Formula: Cu2(Fe, Zn)GeS4
- Colour: gray to gray-blue
- Hardness: 3½ – 4½
- Specific Gravity: 4.337 (Calculated)
- Crystal System: Tetragonal
- Member of: Stannite Group.
Physical Properties of Briartite
- Color: Blue-gray, Gray, Iron gray.
- Density: 4.5
- Diaphaneity: Opaque
- Hardness: 3.5-4 – Copper Penny-Fluorite
- Luster: Metallic
- Transparency: Opaque
Occurrence: As rare inclusions in other Ge–Ga-bearing sulfides.
Association: Chalcopyrite, tennantite, reni´erite, germanite, galena, sphalerite.