saltwater pearl

A saltwater pearl is a gem formed within a mollusk, specifically certain types of saltwater oysters. It is composed of nacre, also known as mother-of-pearl, which is the same material that lines the mollusk's shell. Pearls are valued for their translucence, luster, and the subtle play of color on their surface, called orient.12

The formation of a pearl begins when a foreign particle irritates the mollusk's mantle. In response, the mollusk secretes layers of nacre around the irritant, gradually forming a pearl. The color of pearls can vary widely, including white, cream, gray, blue, yellow, lavender, green, mauve, and black, with the rose hue of Indian pearls being particularly esteemed.12

While edible oysters produce lusterless pearls, the finest natural pearls come from specific Oriental oyster species, notably those found in the Persian Gulf and the Gulf of Mannar. The value of a pearl is determined by its shape, size, luster, and color.13