Antimonite from Yunan/China

In chemistry, an antimonite refers to salts of antimony(III), such as NaSb(OH)4 and NaSbO2 (metaantimonite) which can be prepared by reacting alkali with antimony trioxide, Sb2O3.[1] These are formally salts of antimonous acid (antimonious acid[2]), "Sb(OH)3" whose existence in solution is dubious, and attempts to isolate it generally form Sb2O3.xH2O, antimony(III) oxide hydrate, which slowly transforms into Sb2O3. In geology, the mineral stibnite, Sb2S3, is sometimes called antimonite. They can be compared to antimonates, which contain antimony in the +5 oxidation state.

 
Antimonite