echinite

例句：

1. 1. The echinite formations are a unique feature of the area.
   角石形成是该地区的独特特征。
2. 2. The echinite is a mineral that is commonly found in limestone caves.
   角石是一种在石灰石洞穴中常见的矿物。
3. 3. The echinite has been used for centuries as a decorative stone.
   角石被用作装饰石有数百年的历史。