Formula: S₈

Species: Native Elements

Colour: Yellow, sulphur-yellow, brownish or greenish yellow, orange, white

Lustre: Resinous, Greasy

Hardness: 1½ – 2½

Specific Gravity: 2.07

Crystal System: Orthorhombic

Member of: Sulphur Group

Name: A name in Middle English introduced at least as early as 1390. Also known as brimstone. Theophrastus (~300 BCE) wrote μαλώδης (an otherwise unknown word) for what may be sulfur impregnated pumice, but the actual word should have been μηλώδης meaning quince-yellow. Other interpretations have been given.

Polymorph of: Clinosulphur, Rosickýite, Sulphur Group.
Crystals are usually yellow to yellowish-brown blocky dipyramids, with thick tabular and disphenoidal crystals less common. Also found more typically as powdery yellow coatings. Most native sulfur is found in sedimentary rocks, where large deposits are formed by reduction of sulfates, often biogenically. Sulphur is a common deposition product from volcanic gases associated with realgar, cinnabar and other minerals. It is also found in some vein deposits and as an alteration product of sulphide minerals.
Sulphur crystals have been grown in the laboratory on white Sicilian matrix. Some of the specimens are indistinguishable from good natural specimens. If the crystals grew on a broken surface they could be dismissed as fakes as the crystals had to grow after the surface was broken in mining. In general, a sensitive test was given that indicated the presence of carbon disulfide, the medium in which the crystals were grown. The presence of bitumen on the matrix spoiled the process, so any such specimen is not faked this way. Isotopic analysis could spot these fakes as the sulfur used was from a salt dome and not the sedimentary Sicilian deposit. Had the fakes been made with Sicilian sulfur only the carbon disulfide test could expose them.