Sulphur (S), from the latin verb for “to burn”, sulpur, is a yellow crystalline element that forms many compounds with distinctive odours. It is also a vital part of several major proteins and vitamins.

Sulphur is one of the few elements that is sold in its pure form to consumers. It can be found in gardening stores, pharmacies, and health-supplement stores.

Sulphur can be ignited and will burn with a dull blue flame for a long time. This effect and the smell of sulphur dioxide emanating from it are mentioned frequently in the Bible in descriptions of Hell, where sulphur is referred to as brimstone.