agnesite

例句：

1. 1. The agate is a beautiful piece of jewelry.
   这块玉石是一块美丽的珠宝。
2. 2. The ancient civilizations used agate to make tools and weapons.
   古代文明用玉石制作工具和武器。
3. 3. The agate was polished to a high shine.
   玉石被打磨得非常光滑。