“A diamond in the rough” means that diamonds are often found in the rough, or that a genuine diamond is not always in the same crystal shape. Therefore, it is said about the persons who are genuinely good, but they lack manners and good social upbringing. It is also stated about persons who are harsh by appearances, and this covers their good and positive qualities.
The origin of “a diamond in the rough” has been recorded in the book A Wife for a Month by John Fletcher. The book was first published in 1624 using this phrase as “She is very honest and will be as hard to cut as a rough diamond.”
Example in Sentences:
Example #1: This phrase is mostly used as a metaphor such as “You cannot judge him as he is a diamond in the rough.
Example #2: He does not know how to identify a diamond in the rough.
Example #3: He has been rotting his talent by staying as a diamond in the rough.