opal agate

例句：

1. 1. The opal in the necklace is worth thousands of dollars.
   项链中的琥珀价值数千美元。
2. 2. The opal mines are located in the southwestern part of the country.
   这些琥珀矿位于该国西南部。
3. 3. The opal is a beautiful gemstone that has been prized for centuries.
   这种宝石是一块美丽的宝石，被人们珍视了几个世纪。