A process of making aluminum oxynitride powder including the steps of: forming a powder mixture by mixing alumina powder and aluminum nitride powder according to the following formula: ((4-x)/3) alumina and x aluminum nitride wherein x is in mole percent and ranges between about 0.31 and about 0.61; adding between about 0.1 mole percent and about 1.0 mole percent of pure aluminum powder to the powder mixture; and reacting the powder mixture containing aluminum at a temperature between about 1600.degree. C. and about 1900.degree. C. for a duration between about 2 hours and about 24 hours in a flowing nitrogen atmosphere so as to form aluminum oxynitride.