Patent ID: 7510585

Claim:
Amorphous material comprising at least 35 percent by weight Al 2 O 3 , based on the total weight of the amorphous material, and a metal oxide other than Al 2 O 3 , wherein the amorphous material contains not more than 10 percent by weight collectively As 2 O 3 , B 2 O 3 , GeO 2 , P 2 O 5 , SiO 2 , TeO 2 , and V 2 O 5 , based on the total weight of the amorphous material, wherein the amorphous material lacks any long range crystal structure as determined by X-ray diffraction, wherein the amorphous material has x, y, and z dimensions each perpendicular to each other, wherein each of the x, y, and z dimensions is at least 5 mm, and wherein the amorphous material has a density of at least 85 percent of theoretical, with the proviso that if the metal oxide other than Al 2 O 3 is CaO or ZrO 2 , then the amorphous material further comprises a metal oxide other than Al 2 O 3 , CaO, and ZrO 2 at least a portion of which forms a distinct crystalline phase when the amorphous material is crystallized, and if the metal oxide other than Al 2 O 3 is CaO, then the CaO is present up to 10 percent by weight, based on the total weight of the amorphous material.