Sulfides: Stibnite

Composition: Sb₂S₃

Crystal system: Orthorhombic; columnar or needle-like (acicular) crystal aggregates common images)

7.13.1
stibnite crystals
Malaysia

Properties:

• Metallic lustre
• Lead-grey color,
• Lead-grey streak
• Fingernail scratches (Mohs Hardness 2)
• High density
• Perfect single cleavage; flakes are flexible rather than elastic or brittle
• Cleaves rather than fractures
• Not ferromagnetic
• Dissolves in hydrochloric acid (HCl)

Occurrence:

Stibnite is the most common antimony mineral. It occurs with other sulfides in hydrothermal vein and replacement ore deposits .

Stibnite is an important source of antimony. Most antimony pollution is the result of combustion of fossil fuels rather than antimony mining or processing.