针状体

例句：

1. 1. The crystals are arranged in a hexagonal pattern, resembling a pinwheel.
   这些晶体以六边形的图案排列，就像风车一样。
2. 2. Spinels are commonly found in minerals such as garnet and tourmaline.
   石榴石和托马林等矿物中常见到针状体。
3. 3. The study of spinels is important for understanding the properties of materials.
   研究针状体对于理解材料的性质非常重要。