corundum
US /kəˈrʌndəm/
UK /kəˈrʌndəm/
名詞
剛玉
a very hard mineral consisting of aluminum oxide, occurring in crystalline form as sapphire or ruby and used as an abrasive
範例:
•
Sapphire and ruby are both forms of corundum.
藍寶石和紅寶石都是剛玉的一種。
•
Due to its hardness, corundum is often used in abrasives.
由於其硬度，剛玉常用於磨料。