Pearls and Mother-of-Pearl
The Gemological Institute of America Inc (GIA) calls Pearls the best-loved gems of all time. The most familiar colors are white and cream (a light yellowish brown). Black, Gray, Brown and Silver are also common--but the range of pearl colors extends to every hue. The main color, or body color, is often modified by additional colors called overtones, which are typically pink or rose, green, purple, or blue. Some pearls also show an iridescent quality phenomenon known as orient. When a pearl is formed, a layer of nacre is deposited around a tiny particle that becomes lodged in the mollusk. The nacre is a blend of minerals secreted by oysters and other mollusks and deposited inside their shells--it is a coating that protects them from parasites and foreign objects. Eventually, this nacre builds around the small object and becomes a pearl. As its name implies, Mother-of-Pearl is the inner or “mother” layer of the shell in which a pearl is formed--Literally, it is the genesis material that binds microcrystals to form natural and cultured pearls. The beautiful luster and iridescent play of color can range from white, to pink, lavender, golden brown, gray-beige and amber, and even a dark blue-green, which is seen in the Mother-of-Pearl from the Paua shells in New Zealand. Paua shell Mother-of-Pearl is also called “Sea Opal” because of its vivid color effects and striking iridescence.