jewels
A jewel is a precious stone used to decorate valuable things that you wear, such as rings or necklaces.
a golden box containing precious jewels.
一个装着贵重宝石的金盒子。
If you describe something or someone as a jewel, you mean that they are better, more beautiful, or more special than other similar things or than other people.
gem
a small jewel of a theatre.
一个极好的小剧场。
jewel in someone's crown
If you refer to an achievement or thing as the jewel in someone's crown, you mean that it is considered to be their greatest achievement or the thing they can be most proud of.
His achievement is astonishing and this book is the jewel in his crown.
他成就斐然,这本书是他的最得意之作。