Abalone Pearl: A naturally cultivated pearl from an abalone, which is a univalve mollusk.

Akoya Cultured Pearls: Pearls produced by deliberate human intervention in several varieties of saltwater mollusks generally found in the waters around Japan and China. The Akoya pearl ranges in color from cream, white, rose, gold and blue-gray, and remains justly famous in the hierarchy of cultured pearls for its spectacular luster and beauty.

Baroque: A cultured pearl that is asymmetrical and free form in shape.

Biwa Pearl: A cultured pearl cultivated in a freshwater mussel in Lake Biwa, in Japan. Recently, the term has been allowed to refer to any pearl cultivated in a freshwater mussel in Japan.

Conch Pearl: Similar in color to pink coral, these pearls are produced by a conch, which is a saltwater mollusk from tropical waters.

Cultured Pearl (also "Cultivated Pearl"): A pearl grown in a mollusk that has been surgically implanted with an irritant, through human intervention.

Freshwater Cultured Pearl: A cultured pearl cultivated in a freshwater mollusk from a lake, river or pond.

Imitation Pearl: Man- or machine-made pearls.

Keshii Pearl: Also known as a Seed Pearl. It is a non-nucleated pearl produced accidentally as a by-product of the cultivating process, and consequently not considered a natural pearl.

Mabe Pearl: A dome-shaped cultured pearl cultivated on the inner shell of a mollusk rather than in its body.

South Sea Cultured Pearl: Ranging in hues of white, gold, silver, cream and champagne, these cultured pearls are quite large and are cultivated in the white-lip oyster.

Tahitian Cultured Pearl: Cultured pearls cultivated in the black-lip oyster found in French Polynesia, and producing pearls in natural tints of black, silver, gray, green, orange, gold, blue and purple.