Sulfur

Formula: S

Origin of name: from Latin sulfurum = sulfur

Crystal system: orthorhombic

Crystal class: 2/m 2/m 2/m

Twinning: rare on {101}, {011} or {110}

Unit cell: a = 10.45 Å, b = 12.84 Å, c = 24.46 Å

Colour: sulfur yellow to yellowish brown, yellowish gray

Diaphaneity: 

Luster: resinous to greasy

Habit: crystals bipyramidal, thick tabular or disphenoidal, massive, crusts, stalactites, powdery

Hardness: 1.5 to 2.5

Specific gravity: 2.07

Cleavage: 4; {001}, {110} and {111} imperfect, {111} parting

Tenacity: conchoidal to uneven, brittle

Streak: white

Synonyms/varieties: selensulfur (Se-rich variety), sulfurite, sulphur

Comments: dimorphous with rosickyite