The most common color for pearls is white, cream, pink, purple, but they also come in colors such as champagne, chocolate, blue, gold, silver and lavender. Some pearls have stunning overtones that exhibit multicolors.
Although humans now successfully culture pearls and create them in controlled environments, there are still certain aspects of the process that they have little control over. One such aspect is the color of the pearl. While there are some ways to influence this, most times this is simply left to chance. The organic nature in which the pearl is created means that there are many factors that can influence the color of the pearl.
Here are some of the aspects that can affect the color of a pearl:
Type of Mollusk
Pearl colors are mainly influenced by the color of the mollusks lip, which refers to the outer part of the shell. For example, the famous black Tahitian pearls come from the Pinctada margaritifera oyster, commonly known as the black-lip pearl oyster, which has gray and silver tints at the outer edges of its shell. This is the only mollusk that can form natural black pearls. Another popular variety is the silver lipped oyster (Pinctada maxima) which is known for creating the luxurious South Sea pearl variety.
Thickness of Nacre
Just in case you were wondering, the nacre refers to the substance that the mollusk uses to layer the irritant placed within it. Over time, this grows into the pearl. In general, the thicker the nacre, the deeper and richer the color of the pearl. The thickness of the nacre also affects the pearl’s iridescence, with thin nacre usually creating milky pearls with little to no overtone.
Sometimes, pearl manufacturers can influence the color of the pearl by using various culturing techniques. One main way is to include tissue from an additional oyster into the host oyster as well as the nucleus.
Dyeing the Pearl
Dyeing the pearl is another way to change the color of the gemstone. For example, any black pearl you see on the market that is not a Tahitian pearl, has been dyed. This includes black Akoya pearls.