Opal Facts: The opal stone is October's official birthstone. It's also tradition for an opal to be given on the 14th wedding anniversary. Silica spheres inside the opal reflect a rainbow of light, giving the opal a beautiful array of colors. Common opals have a milky white base and when turned, the colors become evident. Black opal is the rarest form of the stone. It is half the hardness of a diamond and should be periodically soaked in water to reabsorb lost moisture and never cleaned with harsh chemicals or an ultrasonic machine. Australia is the leading miner in opals. Read more »
