Zircon: Used as a gemstone and an ore of zirconium.
Zircon sand has a low expansion coefficient and is very stable at high temperatures. It is used as a refractory material in many foundry and casting applications. One of its most common uses is in the production of ceramics. Zirconium dioxide (zirconia) is produced by heating zircon sand to a high enough temperature to break down the zircon ...