Description Zirconium is found in abundance in S-type stars, and has been identified in the sun and meteorites. Analyses of lunar rock samples show a surprisingly high zirconium oxide content, compared with terrestrial rocks. Some forms of zircon have excellent gemstone qualities.
Zirconium is a grayish-white lustrous metal.
The finely divided metal may ignite spontaneously in air, especially at elevated temperatures. The solid metal is much more difficult to ignite. The inherent toxicity of zirconium compounds is low. Hafnium is invariably found in zirconium ores, and the separation is difficult. Both values are quoted on the Pauling scale.