SulfideIn chemistry, a sulfide (sulphide in British English) is a combination of sulfur with an oxidation number of -2, with another chemical element or a radical thereof. A few covalent sulfur compounds, such as carbon disulfide (CS2) and hydrogen sulfide (H2S) are also considered to be sulfides.
Hydrogen sulfide gas has the odor of rotten eggs, and is also highly toxic. It is formed biologically in the sediments of swamps and in the treatment of sewage sludge by anaerobic digestion of sulfur containing proteins, or bacterial reduction of sulfates. It also occurs in the emissions of some volcanoes, and as a byproduct of some industrial processes.
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2 Natural occurrence
Many important metal ores are sulfides. Significant sulfide minerals include:
- arsenopyrit/mispickel (arsenic and iron)
- argentite (silver)
- chalcopyrit/copper pyrites (iron and copper)
- cinnabar (mercury)
- galena (lead)
- pyrites (iron)
- realgar (arsenic)
- stibnite (antimony) and
- zinc blend/sphalerite (zinc).
SafetyMany sulfides are significantly toxic by inhalation or injection, especially if the metal ion is toxic. Additionally many sulfides, when exposed to a strong mineral acid, will release toxic hydrogen sulfide - and this includes your stomach acids!
See also sulfate, sulfite.