特殊用法black corundum1.黑刚玉common corundum1.普通刚玉electro-melting corundum1.电熔刚玉pulverized corundum1.刚玉砂， 金刚砂粉sintered corundum1.烧结刚玉synthetic corundum1.人造刚玉， 合成刚玉
