Ag8CuSbS6

Ag8CuSbS6 is a quaternary sulfosalt mineral. It belongs to the tetrahedrite group, which is characterized by a complex cubic crystal structure with the general formula Cu12Sb4S13, though Ag8CuSbS6 represents a specific intermediate composition within this broader mineral family. The mineral is named for its constituent elements: silver (Ag), copper (Cu), antimony (Sb), and sulfur (S). Its chemical formula, Ag8CuSbS6, indicates a specific ratio of these elements, though variations can occur in natural samples.

Ag8CuSbS6 typically occurs as microscopic grains or aggregates within hydrothermal vein deposits. It is often found associated with other sulfosalt minerals, such as tetrahedrite, tennantite, and pyrargyrite, as well as common ore minerals like galena and sphalerite. The color of Ag8CuSbS6 is generally dark gray to black, with a metallic luster. Its hardness is typically around 3 to 4 on the Mohs scale, and it has a relatively high specific gravity.

The mineral's formation is linked to low to intermediate temperature hydrothermal processes, where sulfur-rich fluids interact with metallic elements. While not a primary ore mineral for any specific metal, Ag8CuSbS6 can contribute to the overall silver and copper content in some polymetallic deposits. Its identification often requires detailed mineralogical analysis, including microprobe studies, due to its fine-grained nature and similarity to other sulfosalts.