[T]he diamond and other precious stones are focuses of light, and essences of colour which seem expressly created to ornament on a small scale the human body with all the splendours which adorn the universe on a large scale. – Charles Blanc, Art in Ornament and Dress, 1875

In diving to the bottom of pleasure we bring up more gravel than pearls. – Honore de Balzac

A fine quotation is a diamond on the finger of a witty person, but a pebble in the hands of a fool. – Author Unknown

Many individuals have, like uncut diamonds, shining qualities beneath a rough exterior. – Juvenal