sulfide mineral, any member of a group of compounds of sulfur with one or more metals. Most of the sulfides are simple structurally, exhibit high symmetry in their crystal forms, and have many of the properties of metals, including metallic lustre and electrical conductivity.

Some examples of sulfides include galena ( the principle ore mineral for lead and silver), cinnabar (the main ore mineral for mercury), and chalcopyrite (which provides copper).

Pyrite (FeS₂) is by far the most abundant sulfide mineral. The very fine particle iron sulfides found in reducing environments beneath the surfaces of recent sediments and soils, although transient species, are also volumetrically important.

It is produced when bacteria break down plant and animal material. This often happens in stagnant waters with low oxygen content, such as bogs and swamps. Hot springs and volcanoes are other natural sources of hydrogen sulfide. Hydrogen sulfide can also be produced from human, agricultural, and industrial activities.