a diamond in the rough

someone or something whose good qualities are hidden This film is one of those diamonds in the rough, a wonderful gem that almost no one has noticed.

Etymology: based on the idea that you cannot see the beauty of a diamond (jewel) when it is rough (not yet cut and filled with brightness)

Name	Pronounced	Usage
Sezim	-	Kazakh
DraŽEn	-	Croatian, Serbian
Juda	-	Arabic
Valentine (1)	VAL-ən-tien	English
Irma	EER-mah (German, Finnish), UR-mə (English)	German, English, Dutch, Finnish, Spanish, Italian, Georgian, Lithuanian, Hungarian (Rare), Ancient G
Saverio	-	Italian