• Glossary of Pearl Terms T

    Here is a list of pearl terms that might help you better understand this site and the discussions within the community forum. It is compiled from multiple sources and we believe it to be one of the most comprehensive lists available.

    A | B | C | D | E | F | G | H | I | J | K | L | M | N | O | P | Q | R | S | T | U | V | W | X | Y | Z

    Tahitian cultured pearl: Produced by a black-lip mollusk (Pinctada margaritifera) in French Polynesia.

    Tahiti cultured pearl: Produced by a black-lip mollusk (Pinctada margaritifera) in French Polynesia.

    Tahiti Black Pearl Promotion Association: Founded in 1994 to promote Tahitian cultured pearls in the United States.

    Takara pearl: Imitation pearl made with a mother-of-pearl nucleus.

    tank: Indian unit of weight equal to 72 grains or 24 ratis.

    Tavernier, Jean Baptiste (1605 to 1688): Frenchman of great influence in the natural pearl trade who developed a system of grading known as ?Tavernier?s Rule.?

    Tavernier?s Rule: Seventeenth century valuation procedure that multiplies the size factor, or grain weight of a pearl, by itself, and then by a quality factor ranging from 0.5 to 30 that is based on shape, color, luster and surface to arrive at the value of a natural pearl.

    te ufi: Term for black-lip mother of pearl used by original inhabitants of French Polynesia.

    teri: Japanese term for luster.

    third-generation cultured pearl: Freshwater or saltwater cultured pearl whose growth is started either by implanting a shell bead nucleus in an existing pearl sac from which a second-generation cultured pearl was removed, or by letting the mollusk grow a beadless cultured pearl in an existing pearl sac from which a second-generation cultured pearl was removed.

    third graft: Cultured pearl grown in an existing pearl sac after the second harvest. The term is inaccurate because no tissue graft is involved.

    three-quarter cultured pearl: Bead-and-tissue-cultured pearl, most often akoya, that is worked to remove an imperfection, leaving a flat portion of the nucleus exposed. The flat side is usually half-drilled and mounted on a post in a setting that conceals the worked side.

    tinting: Dilute color dye treatment that produces a slight change in a pearl?s color, usually making it pink.

    tissue-cultured pearl: Freshwater cultured pearl whose growth is started by implanting a donor-mollusk mantle-tissue piece in a host mollusk?s mantle.

    tissue method: Implanting a freshwater host mussel with a donor-mussel mantle-tissue piece to start the growth of a beadless cultured pearl.

    Tonen-mono: Japanese term for cultured akoya pearls grown for under one year.