A diamond in the rough is someone who has potential, a person who will achieve success with the right care and polish. When a diamond is found in nature or in the rough, it needs the right care, cut and polish in order to achieve its potential. A diamond in the rough is a metaphor, or a figure of speech that is symbolic of an abstract idea. There is a similar saying in Japanese, tama migakasareba hikari nashi, which translates as a jewel, unless polished, will not sparkle. The term diamond in the rough dates back at least to the 1870s, though the term rough diamond dates back as far as the 1600s.
Examples
“We saw a huge opportunity, essentially a diamond in the rough, on the south side.” (The Arizona Daily Star)
It’s crunch time, Baltimore needed to add an arm and with the starting pitching market as weak as it is this year, Miley could easily turn out to be the diamond in the rough that leads the Orioles back to the playoffs. (Forbes Magazine)
Thus, “Hooked on Antifreeze” proves to be an honest-to-god diamond in the rough, a testament to the good that can be done in the self-published market when the writer actually knows their business. (The Fairbanks Daily News-Miner)
What she’s most impressed by are the droves of people who have discovered what she considered to be the diamond in the rough of mountain biking. (The Grand Junction Daily Sentinel)
In addition, he may find a diamond in the rough or someone who may come out of nowhere with a chance to make the Eagles 53-man roster. (The Philadelphia Tribune)
Still, Sofran described Borom as “a diamond in the rough,” which isn’t shocking given that Borom’s first love was basketball. (The Kansas City Star)