What is Stibnite?
Stibnite is an orthorhombic antimony sulfide, prized for long metallic blades and sprays and important as the principal ore of antimony.
Mineralogy and crystal structure
Reference formula: Sb2S3. Stibnite is soft, strongly cleavable and commonly forms spectacular radiating crystals. Its antimony content and fragile blades make it a display mineral rather than a casual handling material. Stibnite is classified with sulfides and has a orthorhombic crystal system. Typical hardness is 2–2.5 on the Mohs scale and specific gravity is approximately 4.5–4.7.
Colour, lustre and habit
Typical colours include lead-grey, silver-grey, black, iridescent. The usual acicular, bladed, radiating habit and metallic, sub-metallic lustre help describe a specimen, but colour alone is not diagnostic.
Formation and notable localities
Stibnite forms in or is associated with low-temperature hydrothermal veins, hot springs and epithermal antimony deposits. Important documented localities include China, Japan, Romania, Peru, Bolivia, Mexico and the United States.
Metallic blades with museum presence
Stibnite is a high-impact collector mineral: long silver-grey crystals turn a small cabinet specimen into a dramatic piece, while association with quartz and realgar records the ore vein.
Collecting and care
Keep dry and supported, avoid touching delicate sprays, heat, dust and abrasive cleaning. Wash hands after handling.
