1N-COUNT 宝石 A gem is a jewel or stone that is used in jewellery. 宝石
...a gold mask inset with emeralds and other gems.
一张镶有翡翠和其他宝石的金面具
SYN precious stone, jewel, stone, semiprecious stone
2N-COUNT 难能可贵的人(或物);令人非常惬意的人(或事物);精品 If you describe something or someone as a gem, you mean that they are especially pleasing, good, or helpful. 难能可贵的人(或物);令人非常惬意的人(或事物);精品 [informal]