Stibnite, also known as antimonite, is a
sulfide mineral with the formula Sb
2S
3. This soft grey material crystallizes in an
orthorhombic space group. Pastes of stibnite powder in fat or other materials have been used since at least 3000 BC as eye cosmetics in the Mediterranean and farther afield; in this use, it is called
kohl. It was used to darken the brows and lashes, or to draw a
line around the perimeter of the eye. Stibnite is also the most important industrial source for the metalloid
antimony. This stibnite crystal, measuring 5.0 cm × 2.8 cm × 1.5 cm (1.97 in × 1.10 in × 0.59 in), was found in the Herja Mine in
Maramureș, Romania.
Photograph credit: Ivar Leidus