玛瑙

例句：

1. 1. The ancient Chinese emperors were known for their collection of precious stones, including the famous jadeand pearls.
   古代中国皇帝以收藏珍贵的石头而闻名，包括著名的玉石和珍珠。
2. 2. The gemstone is said to have been formed over millions of years by the heat and pressure of the earth's crust.
   据说这种宝石是在地球地壳的高温高压下经过数百万年形成的。
3. 3.This piece of jade is highly valued for its rich green color and smooth texture.
   这块玉石因其丰富的绿色和光滑的质地而备受珍视。