The hues of the opal, the light of the diamond, are not to be seen if the eye is too near. – Ralph Waldo Emerson
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