a rough diamond

• n. 未加工的天然钻石；浑金璞玉

a rough diamond的用法和样例：

例句

1. Mrs.White seems to have a devil of a temper, but she is a rough diamond.
   怀特太太看来脾气很坏，但她是个心地很好的人。
2. I know he looks a bit of a rough diamond in his tattered jeans, but apparently he does a lot of good work for local charities.
   我知道他穿着破烂的牛仔裤看上去有些浑金璞玉的样子，但清楚他是为当地的慈善事业做了许多有益的工作。