Corundum, widely used as an abrasive, is a crystalline form of an oxide of which metal?
Aluminium oxide produce aluminium metal, as an abrasive owing to its hardness, and as a refractory material owing to its high melting point. Corundum is the most common naturally occurring crystalline form of aluminium oxide. Rubies and sapphires are gem-quality forms of corundum, which owe their characteristic colors to trace impurities. Rubies are given their characteristic deep red color and their laser qualities by traces of chromium. Sapphires come in different colors given by various other impurities, such as iron and titanium. AlO is an electrical insulator but has a relatively high thermal conductivity () for a ceramic material. Aluminium oxide is
Indium(III) oxide Indium(III) oxide Indium(III) oxide (InO) is a chemical compound, an amphoteric oxide of indium. Amorphous indium oxide is insoluble in water but soluble in acids, whereas crystalline indium oxide is insoluble in both water and acids. The crystalline form exist in two phases, the cubic (bixbyite type) and rhombohedral (corundum type). Both phases have a band gap of about 3 eV. The parameters of the cubic phase are listed in the infobox. The rhombohedral phase is produced at high temperatures and pressures or when using non-equilibrium growth methods. It has a space group Rc No. 167, Pearson symbol hR30, a