- a soft mineral, antimony sulfide, Sb2S3, lead-gray in color with a metallic luster, occurring in crystals, often acicular, or in bladed masses: the most important ore of antimony.
- a soft greyish mineral consisting of antimony sulphide in orthorhombic crystalline form. It occurs in quartz veins and is the chief ore of antimony. Formula: Sb 2 S 3
