Briartite
Briartite is an opaque iron-grey metallic sulfide mineral, Cu2GeS4 with traces of Ga and Sn, found as inclusions in other germanium-gallium-bearing sulfides.
It was discovered at the Prince Léopold Mine, Kipushi, Shaba, Congo 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.
