金刚砂

例句：

1. 1.The diamond is the hardest material on earth.
   钻石是地球上最硬的材料。
2. 2. Diamondsare used in jewelry and industrial applications.
   钻石用于珠宝和工业应用。
3. 3. Diamonds are known for theirdurability and brilliance.
   钻石因其耐用性和光泽而闻名。