mineral

Stibnite (antimonite)

Stibnite, Sb₂S₃

AI-generated identification · may be incorrect

Metallic lead-gray to steel-gray crystals with elongated, striated blades; Mohs hardness 2, perfect cleavage, orthorhombic crystal structure, and high specific gravity (~4.6).

Identified September 22, 2026More mineral →

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Physical properties

Metallic lead-gray to steel-gray crystals with elongated, striated blades; Mohs hardness 2, perfect cleavage, orthorhombic crystal structure, and high specific gravity (~4.6).

Formation & geological history

Forms in hydrothermal veins and hot-spring deposits as antimony sulfide, commonly with quartz and other sulfide minerals. Deposits range in age and occur in many geological settings.

Uses & applications

The chief ore of antimony, used in flame-retardant materials, alloys, and some battery and chemical applications; attractive crystal clusters are collected as mineral specimens.

Geological facts

Large stibnite crystals can be strikingly flexible and brittle, and historic specimens from Ichinokawa, Japan, are renowned for exceptionally long crystals.

Field identification & locations

Identify by its heavy feel, metallic-gray color, and long, grooved blade-like crystals; notable deposits occur in China, Japan, Romania, and the western United States. Handle gently: crystals are brittle, and avoid creating or inhaling dust.