Bismuthine

Bismuthine, also known as bismuthane, bismuth hydride, and hydrogen bismuthide, is a chemical compound. Its chemical formula is BiH3. It has bismuth and hydride ions in it. The bismuth is in its +3 oxidation state.
Properties.
Bismuthine is very unstable. It is only found below -60°C. Above that temperature it breaks down into bismuth and hydrogen. 
Preparation.
It is made by a complex process that involves organic chemistry.
Uses.
It is part of a test for bismuth. This is similar to the Marsh test for arsenic.