Fused corundum (zirconium oxide ceramic) is a material of the so-called mixed ceramics and is created by combining different oxides. Aluminum, zirconium and silicon oxides are melted in an electric arc furnace at around 2.000 °C. Due to its composition of approx. 50% corundum, approx. 32% zirconium oxide, a glass phase proportion of approx. 18% and the way it is manufactured, zirconium oxide ceramic is often referred to as "fused corundum".