A crucible comprising Al.sub.2O.sub.3 and at least one selected from rare
earth oxides inclusive of Y.sub.2O.sub.3 as main components and
characterized by firing at 500 1,800.degree. C., the distribution of the
rare earth oxide at a higher proportion in a fine particle portion having
a particle size of up to 0.5 mm than in a coarse particle portion having
a particle size in excess of 0.5 mm, and the substantial absence of the
reaction product of the rare earth oxide with Al.sub.2O.sub.3 is suitable
for the melting of a rare earth alloy.