Hi Chen Tai Yu,

First, the correct expression is "diamond in the rough". Second, yes, we use this expression in Britain. Third, since the expression means "a person whose goodness is hidden by a harsh appearence", yes, in certain contexts you could use the expression "he's our diamond in the rough".

<a href="https://en.wiktionary.org/wiki/appearance" title="appearance">I hope this helps!</a>

<a href="https://en.wiktionary.org/wiki/appearance" title="appearance">Matt
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