why do pearls have a color dark

Why do pearls have a color dark

The color of cultured pearls has many reasons, namely organic pigments and chemical composition associated with the reservoir in which the pearl shell is grown (for example, seawater and freshwater have different concentrations of manganese, affecting the color of mother of pearl). The type of pearl clam is undoubtedly one of the essential factors in this process, especially the donor sample that provides the mantle tissue graft (known as sambo).
Which inject into the gonads or mantle (depending on the cultivation method)
Xenotransplantation experiments (meaning a graft from one species to a host mollusk of another species) have demonstrated that the genetic characteristics of the graft mainly determine the color in cultured pearls.
In addition, understanding the mechanisms of color is crucial in the laboratory to determine whether the color of pearls is natural or the result of processing (for example, dyeing, heating, bleaching). Fiji has been producing cultured natural-colored pearls decorated with beads, traditional "Keshi" without beads.

A marine biologist and visionary.
He started his "blue economy" project from a pearl farm in his homeland in Savusavu, Fiji, promoting sustainable luxury with the help of marine cultured pearls. In Fiji, the native pearl oyster Pinctada margaritifera typical has mantle tissue cells that secreKeshiunusual earthy-colored mother-of-pearl (visible in the inner shell of mother-of-pearl oysters).
The colors of these cultured pearls also are colored in this way.
He's not necessarily black in the literal sense of the word. More often, it has a color ranging from gray to dark gray. Pearls that look black can be natural or colored.
Near the island of Tahiti, where such pearls cultivate, the term "black pearl" is applied only to dark-colored natural-colored oyster pearls with a black lip. Its color is a characteristic of oyster mother-of-pearl. The darker the black Tahitian pearl, the more valuable it is. The most expensive varieties of Tahitian pearls characterize by a green shade called "green peacock." Pure black pearls without a shadow are considered undesirable and cost 50% less than pearls with a green hue. Additional shades on black pearls can be pink, blue, gold, silver, and reddish-purple.
Black pearls are often processed to improve their color: they are kept in silver nitrate. In this case, an unnatural homogeneous and intense black coating is obtained, which is noticeably different from the bronze or grayish iridescence of unprocessed pearls.