An iridescent material produced as an inner shell layer by certain molluscs, including abalone, turban snails, pearl oysters and freshwater pearl mussels. Mother of pearl has been used for decoration on furniture, jewelry, utensils, firearms, and musical instruments. Also called nacre.

Engraved mother of pearl pendant. Solomon Islands. Before 1838. Musée de Toulouse, France. Photo: Didier Descouens.