There is in them a softer fire than the ruby, there is the brilliant purple of the amethyst, and the sea green of the emerald – all shining together in incredible union. Some by their splendor rival the colors of the painters, others the flame of burning sulphur or of fire quickened by oil. – Pliny, about the opal

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

Do not judge from mere appearances; for the lift laughter that bubbles on the lip often mantles over the depths of sadness, and the serious look may be the sober veil that covers a divine peace and joy. The bosom can ache beneath diamond brooches; and many a blithe heart dances under coarse wool. – Edwin Hubbel Chapin