刚玉

例句：

1. 1. The gemstone is known for its deep blue color and high hardness.
   这种宝石以其深邃的蓝色和高硬度而闻名。
2. 2. The emerald is a symbol of wealth and prosperity in many cultures.
   绿宝石在许多文化中象征着财富和繁荣。
3. 3. The diamond is often used as a symbol of love and commitment.
   钻石常常被用作爱情和承诺的象征。