Zircon << ZUR kon >> is a mineral composed chiefly of the elements silicon, oxygen, and zirconium. It is a silicate (see Silicate). Zircon contains smaller amounts of other elements, including hafnium, iron, and the lanthanides. Some zircons also contain the radioactive elements thorium and uranium. Zircon crystals may be reddish-brown, yellow, green, blue, or colorless. They resemble prisms with pyramid-shaped ends. The crystals occur in alkali basalts, granites, and other igneous rocks (see Igneous rock). Zircon is resistant to weathering, so it is also found in gravel and sand produced by the erosion of igneous rock.
Zircon is the world’s main source of zirconium and hafnium. These metals are used in the ceramics industry and in making parts for nuclear reactors. Large zircon crystals are used for jewelry. Zircon is a December birthstone.
