brimstone

Brimstone is a historic name for elemental sulfur, the pale yellow nonmetal with symbol S and atomic number 16. It occurs as native sulfur in volcanic regions and is also produced as a byproduct of petroleum refining and natural gas processing.

In common usage, brimstone refers to sulfur; the term appears in English from the Middle Ages and is often associated with the phrase fire and brimstone in religious contexts.

At room temperature sulfur is a crystalline pale yellow solid. It is insoluble in water, but burns readily when heated, yielding sulfur dioxide and a characteristic acrid odor. Sulfur has low reactivity at ambient conditions but oxidizes in air and glows when burned.

Sulfur has a wide range of industrial applications. It is a raw material for sulfuric acid, essential in fertilizer production. It is used in the vulcanization of rubber, in some fungicides and pharmaceuticals, and historically in gunpowder and matches.

Native sulfur deposits are found near volcanic vents; large-scale production takes place worldwide. Handling sulfur requires caution: burning sulfur releases sulfur dioxide, an irritant; inhalation exposure should be minimized.

In culture, the phrase fire and brimstone is used to describe hellfire and brimstone rhetoric.