Although mother-of-pearl and pearls may appear identical, their production, appearance, and jewelry applications are very different. The iridescent layer that lines the inside of mollusk shells, particularly those of oysters and abalones, is called mother of pearl, or nacre. It is extracted from the interior of the shell, revealing a finish that resembles a rainbow.

Conversely, pearls are spherical gems that develop when nacre covers an irritant that is imprisoned inside a mollusc. While pearls are mostly used in fine jewelry like necklaces, earrings, and rings, mother of pearl stone is frequently used for inlays, watch dials, and decorative items. Mother of pearl is more accessible for more informal, everyday designs because it is typically less expensive than pearls.