... . This is specially supplied for Sapphire related field. Aluminium oxide is the family of inorganic compounds with the chemical ... units of aluminium oxide.Alumina also exists in other phases, namely η-, χ-, γ-, δ- and θ-aluminas. Each has a unique crystal structure and ... substitute for industrial diamond. Many types of sandpaper use aluminium oxide crystals. In addition, its low heat retention and ...