Sulfur (on Matrix)

Physical Properties

Hardness: 1.5–2.5 (Mohs); Color: Bright yellow to pale yellow; Luster: Resinous to earthy; Crystal structure: Orthorhombic; Specific Gravity: 2.07

Formation & Geological History

Formed as a sublimate from volcanic gases at fumaroles, or by the breakdown of sulfide minerals and sulfate reduction in sedimentary environments.

Uses & Applications

Used in the production of sulfuric acid, fertilizer, gunpowder, matches, and insecticides. Collector value as cabinet specimens.

Geological Facts

Sulfur is often associated with the distinct smell of rotten eggs when burned (releasing SO2 gas), though pure sulfur itself is odorless at room temperature. It was known to ancients as 'brimstone'.

Field Identification & Locations

Identify in the field by its distinct yellow color, low hardness (can be scratched with a fingernail), and resinous luster. Often found near hot springs and volcanic vents.

Identified on: 4/22/2026

Mode: Standard