IYPT Elements

IYPT 2019 Elements 040: Zirconium: Jewellery, ceramic knives, and nuclear power

Element 40 in our International Year of the Periodic Table series is zirconium. Its compounds are commonly used in jewellery to simulate diamonds, and in ceramic knives. It also finds use in nuclear power stations.

Cubic zirconia is a form of zirconium dioxide. Due to its similarity in appearance to diamonds, coupled with its much lower cost and wide availability, it’s become the most common diamond competitor. It does show some differences, being softer and of a slightly higher density than diamond. Jewellers can use these differences to distinguish between the two.

Another form of zirconium oxide is used in ceramic knives. As zirconium oxide is much harder than steel, knives made from it stay sharper for longer. However, they are also more brittle than steel knives, and if dropped on a hard surface may shatter.

Elemental zirconium is used to clad the uranium fuel rods in nuclear reactors. It’s used for this purpose because it is a poor absorber of neutrons produced by the fission reaction, meaning the neutrons can pass through. Zirconium’s heat and corrosion resistance is also useful for this purpose.

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.