针晶体

例句：

1. 1. The crystals are so clear that they can be seen through the glass.
   这些晶体如此透明，可以透过玻璃看到。
2. 2. The crystals were formed by a process of slow cooling.
   这些晶体是通过缓慢冷却过程形成的。
3. 3. The crystals have a unique structure that makes them useful in various industries.
   这些晶体具有独特的结构，使其在各种行业中都有用武之地。