Polybasite is a sulfosalt mineral of silver, copper, antimony and arsenic.

Its chemical formula is [(Ag,Cu)6(Sb,As)2S7][Ag9CuS4].

It forms black monoclinic crystals (thin, tabular, with six corners) which can show dark red internal reflections.

It is found worldwide and is an ore of silver.

This article about a specific sulfide mineral is a stub.