FUSED ALUMINUM OXIDES HAVE BEEN THE MINERAL OF CHOICE FOR FERROUS METAL GRINDING SINCE THE BEGINNING OF THIS CENTURY. NO OTHER OXIDE COMBINES THE HARDNESS AND CHEMICAL STABILITY OF THIS PARTICULAR MINERAL, AND ITS CONTINUED USE FOR MANY GRINDING APPLICATIONS WILL CONTINUE INTO THE NEXT CENTURY. MORE RECENTLY, THIS SAME MINERAL HAS BEEN IMPROVED BY A PRODUCTION METHOD RADICALLY DIFFERENT THAN FUSION. BY CHEMICAL SYNTHESIS, AN ALUMINUM OXIDE MADE UP OF SUBMICRON CRYSTAL-LITES HAS BEEN PRODUCED. THIS STRUCTURE EXHIBITS A LARGE INCREASE IN FRACTURE TOUGHNESS WITHOUT LOSS OF THE OTHER PROPERTIES WHICH HAVE MADE ALUMINUM OXIDE SO USEFUL AS AN ABRASIVE GRIT.