Background |  Name |   Sources |  Uses |  Substitutes and Alternative Sources

Background

Bismuth is a silvery-white metallic element with a pinkish tint on freshly-broken surfaces. Its chemical symbol is Bi, and its atomic number is 83. Bismuth was long thought to be a variety of lead or tin, which it resembles, until the chemist Claude Geoffroy showed in 1753 that it is a separate element.

Bismuth is rarely noticed in everyday life. Unlike the more common metals such as copper, lead, and iron, bismuth is rarely noticed by the average person.

Bismuth is relatively brittle for a metal. It has the interesting physical property of being less dense as a solid than it is as a liquid. The only other common substances which expand when they freeze are antimony metal and water. This property of expanding when cooling is responsible for much of bismuth’s commercial uses. Bismuth is a poor conductor of electricity and heat (scientists say it has poor electrical and thermal conductivities). It is relatively stable and does not corrode in the atmosphere, unless attacked by strong acids. Bismuth is not known to have any role in either plant or animal life functions. Importantly, bismuth is non-toxic (not poisonous), unlike lead and most other heavy metals.

Naturally-occurring bismuth metal (known as native bismuth) is rare in nature, and does not occur in large enough quantities to be mined as a source of bismuth. More often it combines with other elements to form minerals such as bismithunite (bismuth sulfide, Bi2S3) and bismite (bismuth oxide, Bi2O3).