A WORD ABOUT PEARLS

Natural pearls are found in oysters and other mollusks. Cultured pearls also are grown in mollusks, but with human intervention; that is, an irritant introduced into the shells causes a pearl to grow. Imitation pearls are man-made with glass, plastic, or organic materials.

Because natural pearls are very rare, most pearls used in jewelry are either cultured or imitation pearls. Fine quality cultured pearls, because they are harvested from oysters or mollusks, are more expensive than imitation pearls. A cultured pearl's value is largely based on its size, usually stated in millimeters, and the quality of its nacre coating, which gives it luster. The pearls color, blemish, type and shape are also considered.