Bismuth(III) oxide is perhaps the most industrially important compound of bismuth. It is also a common starting point for bismuth chemistry. It is found naturally as the mineral bismite and sphaerobismoite, but it is usually obtained as a by-product of the smelting of copper and lead ores. 

Bismuth oxides have been considered as an interesting material because of their dielectric properties and have been used for applications such as optical coatings, metal-insulator-semiconductor capacitors and microwave-integrated circuits.

Bismuth and its salts can cause kidney damage, although the degree of such damage is usually mild. Large doses can be fatal. Industrially it is considered one of the less toxic of the heavy metals.

In its elemental form, bismuth is a silvery white brittle metal. Bismuth is the most diamagnetic of all metals and, with the exception of mercury, its thermal conductivity is lower than any other metal.

BISMUTH OXIDE