玉不琢,不成器 (juk6 bat1 doek3 , bat1 sing4 hei3) — a piece of jade without chiselling will not become a useful vessel; the finest diamond must be cut in Cantonese
jukˍ₆玉batˉ¹不doek˗₃琢,,不batˉ¹成singˎ₄器Mandarin Pinyin: yu4 bu4 zhuo2 , bu4 cheng2 qi4
Meaning of 玉不琢,不成器
nouna piece of jade without chiselling will not become a useful vessel; the finest diamond must be cut