diamond in the rough

US /ˈdaɪ.mənd ɪn ðə rʌf/
UK /ˈdaɪ.mənd ɪn ðə rʌf/
"diamond in the rough" picture
1.

diamante en bruto, talento sin pulir

a person or thing that has great potential but is not yet refined or polished

:
The young artist was a true diamond in the rough, needing only guidance to shine.
El joven artista era un verdadero diamante en bruto, que solo necesitaba orientación para brillar.
The old house was a diamond in the rough, with good bones but in need of renovation.
La casa antigua era un diamante en bruto, con buena estructura pero necesitada de renovación.