Opal (October Birthstone) In the olden days, the Opal was known as the Queen of Gems because it encompassed the colors of all other gems. Because opal has the colors of other gems, the Romans thought it was the most powerful of all. The Bedouins believed that opals contained lightning and fell from the sky during thunderstorms. Each Opal is truly one-of-a-kind; as unique as our fingerprints. With its rainbow of colors, as you turn and move the Opal the color shifts, giving you a gem that can be worn with a plethora of ensembles.