mineral

Sulfur

Native Sulfur (S8)

Hardness: 1.5-2.5 on Mohs scale; Color: bright yellow to yellowish-brown; Luster: resinous to greasy; Crystal Structure: Orthorhombic; Cleavage: imperfect; Specific Gravity: 2.07

Hardness: 1
Color: bright yellow to yellowish-brown
Luster: resinous to greasy

Identified June 21, 2026More mineral →

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Physical properties

Hardness: 1.5-2.5 on Mohs scale; Color: bright yellow to yellowish-brown; Luster: resinous to greasy; Crystal Structure: Orthorhombic; Cleavage: imperfect; Specific Gravity: 2.07

Formation & geological history

Formed as a precipitate from volcanic gasses (fumaroles), by the decomposition of sulfate minerals by bacteria, or within sedimentary evaporite deposits. Most commonly associated with volcanic activity and salt domes.

Uses & applications

Used in the production of sulfuric acid, fertilizers, gunpowder, matches, insecticides, and in the vulcanization of rubber. Historically used in medicine and as a bleaching agent.

Geological facts

Sulfur is known for its distinct 'rotten egg' smell when burned (due to sulfur dioxide), but pure sulfur is actually odorless. It was known in ancient times as 'brimstone' (burning stone).

Field identification & locations

Identified by its bright yellow color, low hardness (can be scratched by a fingernail), and resinous luster. It is highly flammable and melts at a low temperature (~115°C). Found in Italy (Sicily), USA (Gulf Coast), and Japan.