People have prized opals and their play of colors for millennia. Pliny the Elder described opals as “made up of the glories of the most precious gems,” containing “the gentler fire of the ruby,” the “brilliant purple of the amethyst,” and the “sea-green of the emerald, all shining together in an incredible union,” some with bright blue luster and others with that of flames. Crystal opal, 8 cts, with semi-transparency and bright, varied play of color. © Urth Kandi Jewelry. Used with permission.