What are sulfides in mineralogy ?

Sulfides : definition

The class of sulfides and sulfosalts forms a large class with over 570 minerals. This class is primarily concerned with mining as it includes the essential ores of many base metals (except iron, chromium, manganese and a few others).

The sulfide subclass also includes rarer, chemically related compounds: selenides, tellurides, arsenides, antimoniides, sulfoarsenides and sulfoantimoniides.

The general formula of sulfides is of the XmZn type, where X represents the metallic element(s) : the reducing cations. Z represents the non-metallic element(s), the oxidizing anions : S, but also Sb, As, Se or Te for the selenides, antimoniides, etc... which are then in the form As3+, Sb3+.
Stibnite : antimony sulfide
Chalcopyrite : iron and copper sulfide
Pyrite : iron sulfide