stibnite, antimony sulfide, Sb₂S₃, a mineral, silvery gray in color, with a metallic luster. It crystallizes in the orthorhombic system. Found in many parts of the world, it is the most important ore of antimony. It is commonly deposited by alkaline waters and occurs in association with quartz, calcite, sulfides of the base metals, arsenic, gold, and silver. Known in ancient times, stibnite was used in powdered form by women to darken their eyebrows and eyelashes. Antimony is used in alloys for type metal, storage batteries, pewter, babbitt, and antifriction metal for bearings. Its compounds find use in explosives, matches, and fireworks, in vulcanizing rubber, and in medicine as an emetic.

Antimony sulfide (Sb₂S₃), the principal ore of antimony. This sulfide mineral has a brilliant metallic lustre, is lead or steel gray in colour, and fuses (melts) readily. Stibnite occurs in low-temperature hydrothermal veins (see hydrothermal ore deposits) and in replacement deposits. Significant deposits have been found in China, Japan, and the U.S. (Idaho, California, and Nevada). Stibnite is used in making matches, fireworks, and percussion caps and was used by the ancients as a cosmetic (called kohl) to increase the apparent size of the eye.

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