Feldspars are the most abundant minerals in the earth’s crust, and the particular species: orthoclase, that contains moonstones has a history of being worn in jewelry almost as old as civilization. Moonstone is known for its distinct sheen, which ancient Greeks and Romans believed were trapped rays of moonlight. In fact the technical term for this sheen is adularescence; this magical stone was once called adularia deriving from Mt. Adular (now St. Gotthard) in Switzerland where it was once mined. Adularescence is a result of a natural growth pattern of alternating layers of feldspar minerals, orthoclase and albite. This layering causes an interference of light as it enters the stone, reflecting back as the sheen beloved in moonstones, making them appear to glow from within.
Legends say the stone provides good luck, Hindu legend believes it was formed by moonbeams, and in Arab countries, women historically sewed moonstones into their garments to promote fertility. Properties often associated with the moon has been applied to this gemstone, such as romance, femininity, intuition, dreams and love. Long been a favored gemstone in jewelry, designers of the romantic Art Nouveau era, such as René Lalique and Louis Comfort Tiffany, heavily featured moonstone. Like most gemstones, the most prized moonstones contain no visible inclusions; they will also have a colorless, semi transparent to nearly transparent body color with strong vivid adularescence.
Rainbow moonstones also feature prominently in new designs by Omi Prive. Although also a feldspar, rainbow moonstones are from the labradorite species of the group. Labradorite Feldspar is most often associated with mining in Labrador, Canada, but Madagascar is a top source for rainbow moonstone which has a lighter or more transparent body color than traditional Labradorite. Both traditional moonstone and rainbow moonstone’s adularescence is caused by light reflection of twinning planes. With its phenomenal properties, pairing very fine rainbow moonstones with alexandrite accents creates designs that are constantly changing and encourage a deeper examination.