Cupromakovickyite
Cupromakovickyite is an IMA-recognized mineral species in the sulfosalt class, with the chemical formula Cu₄AgPb₂Bi₉S₁₈.
It crystallizes in the monoclinic crystal system (space group C2/m). It is a member of the Pavonite structural group.
Key properties: Mohs hardness 4; specific gravity 6.78; Gray streak; Metallic. Bireflectance: Moderate (oil). Anisotrophism: Strong (oil); dark bluish gray to yellow brown luster.
IMA symbol Cmak, IMA status: approved, named in 2002.
Occurs as exsolution lamellae or discrete grains in association with sulfosalts in contact metamorphic rocks (skarns) around granite and in scheelite-bearing quartz veins in felsic gneisses and amphibolites.
It is found associated with Aikinite-friedrichite, hodrušite, padĕraite, kupčikite, emplectite, wittichenite, tetradymite, chalcopyrite, dolomite (Romania); aikinite-krupkaite, hodrušite.
The name refers to its essential copper content and relationship to makovickyite.