A. Artificial corundum: 2 Brown corundum, white corundum, black corundum, Cr corundum, microlite corundum, single crystal corundum, zirconia corundum, Pr and Nd corundum, sintered corundum;

• 一、人造刚玉：2棕刚玉、白刚玉、黑刚玉、铬刚玉、微晶刚玉、单晶刚玉、锆刚玉、镨钕刚玉、烧结刚玉;