Physical Appearance
Moonstones come in a number of colors -- white, flesh-colored, blue-white, gray, silver, peach, brown, yellow, green, pink and multicolored. They can be distinguished from other gemstones by their luster. The surface of moonstones exhibits an iridescent play of light, which in some types can cause a cat's-eye effect. High-quality moonstones have perfect clarity and transparency, while lesser moonstones are more less translucent. Typically, jewelers cut moonstones into an ovoid dome shape, although they may also be carved.
Chemical Composition
Moonstones come from the intersection of orthoclase feldspar with other silicate minerals, such as albite, perthite, adularia, sandine and peristerite. Chemically, potassium aluminum silicate and sodium calcium aluminum silicate combine uneasily together in moonstones, creating structural gaps in them that result in a "shimmering" effect. This effect, known as "adularescence," gives moonstones their haunting beauty. Soft and rather delicate compared to other gemstones, moonstones can be easily scratched and should be handled with care. Store moonstones away from other, harder gems, and clean them gently with water and dish soap.
Symbolic Significance
Although most deem pearls to be June's official gemstone, moonstones have also been associated with this month. Cultures throughout the ages have thought of moonstones as solidified moonlight, and tied moonstones to various moon goddesses. They also have mythological ties to water, healing, travel, dreams, love and madness. In astrology, moonstones may be linked to the sign of Cancer. Some energy healers believe that moonstones can help balance masculine and feminine energies in the body. It was believed that travelers who carried moonstones could protect themselves from danger.
Uses
Because of their abundance, moonstones come at very affordable prices. After cutting moonstones into cabochons, jewelers set moonstones in rings, mount them in pendants, string them together into necklaces, attach them to earring hooks or use them as the focal point for brooches. In the 19th century, moonstones gained popularity as a gemstone choice for engagement rings.
Wiccans use moonstones for rituals that promote fidelity in lovers. They also believe it can help relieve emotional distress, premenstrual syndrome symptoms, insomnia and nightmares. Ancient peoples put moonstones in their fields and orchards, believing that the power of the stones would help their crops to flourish.