Bismuth is represented by the chemical symbol Bi and has the atomic number 83. It is considered a post-transition metal and is placed near lead, tin, and other heavy metals on the periodic table.
In its pure form, bismuth is a brittle metal that exists as crystals with an iridescent hue. When bismuth is alloyed with other metals, which happens frequently, it forms low-melting alloys that make it useful for applications like solders, fuses, and automatic sprinkler systems.
Bismuth has some standout physical properties including having a high electrical resistance and being diamagnetic. It also has the unusual ability to expand as it solidifies which is the opposite of how water and most other substances behave.
Natural Sources of Bismuth
Bismuth can absolutely be found naturally on Earth. However, it does not occur in its pure elemental form. Instead, bismuth is most often extracted from bismuthinite and bismite ores.
Bismuthinite, also known as bismuth glance, contains up to 81.3% bismuth as well as other metals like cobalt and nickel. Major bismuthinite mining areas are located in Bolivia, Mexico, and Peru. Meanwhile, bismite, or bismuth oxide, is a mineral containing about 89% bismuth that is mined in locations including Australia, Bolivia, and China.
In addition to being concentrated in ores, small or trace amounts of bismuth can be found distributed through Earth's crust and in some bodies of water. Estimates place the concentration of bismuth in the Earth's crust at around 0.008 parts per million.
Bismuth can also occur naturally as a decay product of uranium and thorium. However, the amounts generated this way are incredibly small.
History and Uses
Bismuth has been known since ancient times. Early uses of bismuth date back over 5,000 years and include cosmetics, medicines, and metal alloys.
Even today, bismuth still has some niche uses in the pharmaceutical and cosmetic industries. However, its primary modern uses focus on metallurgy and chemicals. Adding bismuth to metals like lead and tin creates alloys with properties that make them preferable for plumbing, solders, ammunition, and more.
Bismuth is also used to produce specialty chemicals like bismuth oxychloride and bismuth oxynitrate which can act as catalysts, pigments, and fire retardants. A small amount of bismuth is even used to make the active ingredient in some popular over-the-counter heartburn and stomach medicines.
So, while bismuth in its pure form is rare in nature, it can readily be obtained from common bismuth-containing ores. Despite its relative scarcity, bismuth has proved to be an incredibly useful element throughout history and continues to provide value in numerous commercial and industrial applications today. So next time you see that iconic Pepto-Bismol pink, you can be sure it's sourced from bismuth that started deep underground!
