| Vivid, orange, opaque crystals|
Hexasulfur (systematically named hexathiane, and cyclo-hexasulfur) is an inorganic chemical with the chemical formula S
6, consisting of a ring of six sulfur atoms. It is thus a simple cyclosulfane, and an allotrope of sulfur. It is also the final member of the thiane heterocyclic series, where every carbon is substituted with a sulfur atom.
The name hexasulfur, is the most commonly used and preferred IUPAC name, and is constructed according to the compositional nomenclature. The systematic name hexathiane, a valid IUPAC name, is constructed according to the substitutive nomenclature. Another valid IUPAC systematic name cyclo-hexasulfur, is constructed according to the additive nomenclature.