a rough diamond

基本解释

Typically, about 60 percent of a rough diamond is lost as dust or shavings in the cutting process.
典型區別就是，原石大約60%的部分會作爲粉塵除去或是在切割過程中成爲碎料。
He's not a rough diamond--a pearl-containing oyster of a rustic: he's a fierce, pitiless, wolfish man.
他不是一塊粗糙的鑽石——鄕下人儅中的一個含珠之蚌，而是一個兇惡的，無情的，像狼一樣殘忍的人。我從來不對他說，‘放開這個或那個敵人吧，因爲傷害他們是不正大光明的，殘酷的。’
He said I was like a rough diamond and I needed polishing.
他說我就像一塊粗糙的鑽石，需要磨光。

"A rough diamond is pure potential and pure risk, " writes Hart.
FORBES: Fracture Lines
McQueen the teenager lacked the academic credentials for admission, and by Hillson's tell, he was still a very rough diamond at 21.
FORBES: Fashion's Hard Case
De Beers Group reports that high prices and strong demand in India, China, the Middle East and, surprisingly, the U.S. has resulted in a record for rough diamond sales.
FORBES: De Beers Diamond Sales Up 33%