Zirconium. (Source: © Björn Wylezich / stock.adobe.com)

Chemical element with atomic number 40. Zirconium is a gray-white metal highly resistant to corrosion, with a melting point of 1.855 °C. It is found on Earth in more than a hundred types of minerals. Zirconium oxide is used as a substitute for diamonds. Zirconium can be alloyed with other metals to form a so-called zircalloy, which is used for nuclear fuel cladding.