Element 27 in our International Year of the Periodic Table series is cobalt, found in pigments, jet engines, and used in the sterilisation of medical equipment.

If you’re ever dabbled in painting or pottery-making, you may have come across the shade cobalt blue. It’s, as the name suggests, a blue pigment which is both used in paints and as a colouring agent in Chinese porcelain. Chemically, it’s cobalt(II) aluminate.

Alloys of cobalt with other metals find a range of uses, as they stay strong at high temperatures and resist corrosion. In 2010, about half of the cobalt consumed in the U.S. was used to create these alloys, which find uses in jet engines and gas turbines.

Another leading use of cobalt is in the creation of rechargeable batteries. Approximately 50% of cobalt produced worldwide is used for this purpose; it’s used to make the lithium cobalt oxide cathodes found within the batteries. We looked at rechargeable batteries in more detail a few years ago when the Samsung battery fires were in the news.

Cobalt also has medical uses. One of its radioactive isotopes, cobalt-60, is used to irradiate medical equipment, sterilising it. It’s also used for food irradiation; this irradiation can kill bacteria, meaning food keeps for longer, and is safe as it doesn’t make the foods radioactive.

Remember, you can keep track of all of the previous entries in this series on the site here, or on the Royal Society of Chemistry’s dedicated page.