thumb|[[Stibnite (antimonite) - Baia Mare, Herja Mine, Romania.]]
In chemistry, antimonite refers to a salt of antimony(III), such as NaSb(OH)<sub>4</sub> and NaSbO<sub>2</sub> (meta-antimonite), which can be prepared by reacting alkali with antimony trioxide, Sb<sub>2</sub>O<sub>3</sub>. These are formally salts of antimonous acid, Sb(OH)<sub>3</sub>, whose existence in solution is dubious. Attempts to isolate it generally form Sb<sub>2</sub>O<sub>3</sub>·xH<sub>2</sub>O, antimony(III) oxide hydrate, which slowly transforms into Sb<sub>2</sub>O<sub>3</sub>.