The table below gives the different combinations of body color and overtones, and special names used for the combination, in the classification of cultured black Tahitian pearls.Ĭombination of body color and overtones in black Tahitian pearls The fact that the "Black Beauty" is a natural black pearl having the most sought-after color combination as overtones, enhances its value and uniqueness as a famous natural pearl in the world. The blend of rainbow colors with the black body-color of the pearl is known as "peacock" or "rainbow" in the pearl trade, and today is the most sought-after color among the cultured black pearls of Tahiti. The overtone of rainbow colors is actually caused by the interference of light passing through the alternative layers of aragonite and conchiolin of the thick nacre, and so is the orient and iridescence of the pearl. The aragonite platelets which are transparent calcium carbonate crystals, remain colorless, through which the color of the pigment shows through. The pigment combines with the protein component of the nacre known as conchiolin.
The natural black color of the pearl is actually the body color of the pearl, caused by a black melanin pigment secreted by special glandular cells in the mantle, during the formation of the nacre. The natural black color with a blend of rainbow colored overtones, known as "peacock" is perhaps the finest ever seen. The pearl is a high-domed, button-shaped pearl, with dimensions of 10.05 x 8.75 mm, and having a weight of 6.53 carats, equivalent to 26.12 grains. © Smithsonian Institution, photo by Chip ClarkĬharacteristics of the Black Beauty Pearl