a diamond in the rough

• 天然金刚石

a diamond in the rough的用法和样例：

例句

1. CVD diamond thick film is a pure diamond material with full polycrystallinity synthesized by chethecal va-por deposition method.It can be in a thick sheet form of freestanding.
   金刚石厚膜片是采用化学气相沉积的方法制备出来的一种金晶质多晶纯金刚石材料，其物理性能和天然金刚石非常接近，而化学性质则完全相同。
2. In this paper, the high performance of diamond film coated tools were expounded by testing the property of diamond film coating with SEM and comparision with natural diamond.
   用扫描电镜等方式检测金刚石镀膜的性能，并与天然金刚石的相关参数进行比较，阐明了金刚石涂层刀具的优异性能。