Sulphur occurs in volcanic and sedimentary deposits, as well as being a constituent of many minerals and petroleum. It is normally a bright yellow crystalline solid, but several other allotropic forms can be made. Sulphur is an ingredient of gunpowder, and is used in making matches and as an antiseptic and fungicide
Middle English: from Anglo-Norman French sulfre, from Latin sulfur, sulphur
In general use the standard British spelling is sulphur and the standard US spelling is sulfur. In chemistry, however, the -f- spelling is now the standard form in all related words in the field in both British and US contexts.