Aluminia, often referred to in the context of alumina, is a chemical compound made up of aluminum and oxygen, with the formula Al₂O₃. It is a key material in the production of aluminum metal and is also used in various applications such as ceramics, abrasives, and as a catalyst in chemical processes. Aluminia can occur in several forms, including corundum and bauxite, and is known for its hardness and thermal stability.