fresh water pearl

例句：

1. 1. The freshwaterpearl is a rare and valuable gemstone.
   淡水珍珠是一种稀有且珍贵的宝石。
2. 2. The pearlwas found in the freshwater riverbed.
   这颗珍珠是在淡水河床中发现的。
3. 3. Freshwater pearls are often used as decorativeitems.
   淡水珍珠常被用作装饰品。