1.high purity & density alumimum oxide 2.competitive price for sapphire growing 3.types: powder, ball, pellet, crackle High purity Alumina pellet ... pellet, the raw material for sapphire crystal growth is fine processed with high purity alumina powder, which is research and ... ball, the raw material for sapphire crystal growth is fine processed with high purity alumina powder, which is research and ...