- Sulfur or sulphur is a chemical element with symbol S and atomic number 16.
- The element has traditionally been spelt 'sulphur' in the United Kingdom and most of the Commonwealth countries, while the United States used 'sulfur'. The term sulfur is now the standard name used in most contexts.
- Because sulfur is so abundant in its native form the element has been known since ancient times. The Bible refers to sulfur as brimstone meaning 'burn stone' or 'stone that burns'. There have also been recorded uses of sulfur in ancient India, Greece, China and Egypt.
- Elemental sulfur has a bright yellow color at room temperature and is a non-metal flaky crystalline solid. When burned, sulfur melts to a blood-red liquid and burns a bright blue.
- In 1777, French chemist Antoine Lavoisier managed to convince the scientific community that sulfur was not a compound but in fact a basic element.
- The melting point of sulfur is 247.3 °F (119.6 °C) and the boiling point is 832.3 °F (444.6 °C).
- Sulfur is non-toxic in its pure element form and in the sulphate form. But its compounds such as carbon disulphide, hydrogen sulphide and sulfur dioxide are all toxic.
- Mineral collectors like elemental sulfur crystals for their distinct, brightly colored polyhedron (multisided) shapes.
- Sulfur compounds can naturally occur as sulfide minerals such as pyrite, cinnabar, galena, sphalerite and stibnite. Or as sulfate minerals such as gypsum, alunite and barite.
- Pure elemental sulfur is found near hot springs/pools and volcanic areas, most notably in countries around the Pacific Ring of Fire such as Indonesia, Chile, and Japan where these deposits are often mined.
- The pungent smell referred to as "sulfur" that is very distinctive in volcanic areas comes mainly from the compound hydrogen sulfide. In fact hydrogen sulfide and other sulfur forms produced by living organisms are responsible for the awful smell from skunks, rotton eggs and burning hair or feathers.
- Sulfur is an essential element of all living forms. It is one of the top 8 most abundant elements in the human body. For example, a person weighing 70 kg's has about 140 grams of sulfur in them.
- Sulfur is used commercially in fertilizers, in the manufacture of sulfuric acid (one of the most important industrial chemicals), in matches and traditionally in black gunpowder. 'Dusting sulfur' (powdered elemental sulfur) is used in pesticides, insecticides and fungicides and sprayed over fruit and vegetable crops.
- Many meteorites contain sulfide compounds and Jupiter's volcanic moon Io has colorful areas formed by molten, solid and gaseous sulfur.
- The burning of fossil fuels such as coal and oil produces sulfur dioxide which is largely responsible for incidents of ‘acid rain’ that have been known to occur near industrial areas.