Throughout history, gemstones have been revered for their aesthetic value. Several legends surround gemstones. The ancient Greeks and Romans attributed various healing and metaphysical properties to the different gems.
Opal is hardened silica. It measures 7 on the Mohs scale of hardness with 10 being the hardest. Opal comes in a variety of colors including white, black, pink and blue. Moonstone is the most valuable form of feldspar. It measures 6 on the Mohs scale. Moonstone ranges in color from silver gray to peach and has a white or blue sheen.
According to legend, moonstone is thought to possess the qualities of good fortune, protection and heightened intuition. Opal was a symbol of hope and purity to the ancient Romans, and the Greeks believed the gem bestowed its wearer with the ability to see the future.
Moonstone is associated with the moon, the month of June, the element of water and the astrological signs of Cancer, Libra and Scorpio. Opal is associated with beauty and power. It is the modern birthstone for the month of October but is also associated with the astrological signs of Cancer, Libra, Pisces and Scorpio.