Perusing a pearl collection, you might be suprised at how many different colors of pearls there are. You can find pearls in white, cream, pink, purple and black with overtones of green, brown and blue. While personal preference is the basis for deciding which color pearl is best for you, it’s important to understand why pearls are the colors they are.
Oysters secrete nacre to cover a nucleus in their tissue - this is what most pearls are made of. The nacre's thickness determines the color of the pearl. The thicker the nacre, the richer the color of the pearl. The main factor that determines a pearl's color is the type and color of the mollusk that produced it. Different mollusks produced different colors of pearls for a variety of reasons.
Freshwater pearls are found in a wide variety of colors naturally. The colors are produced for many different reasons including environment, type of mussel and the location of the nucleus inserted into the tissue. Manganese is one element found only in freshwater mollusks and causes changes in the pearl’s color. The Manganese will darken freshwater pearls causing a silver-grey effect making a beautiful and unique colored gemstone.
Some pearls’ color, like that of the South Sea pearl, is based on the color of the oyster’s mantle tissue that it came from. The South Sea pearl is produced by the Pinctada maxima mollusk. There are two different variations of this mollusk – the silver lip and the gold lip. The silver lip creates white, silver and rose colored pearls while the gold lip produces yellow, gold and champagne colored pearls. The gold colored South Sea pearls are very rare and possibly the most valuable
Tahitian pearls or black South Sea pearls have a rich, dark coloration. Tahitian pearls are produced by the Pinctada margaritifer mollusk. This mollusk is also known as the black lip oyster. The mantle of the black lip oyster is very dark which causes the pearls it produces to be black in color. The color will not lonly be dependent on the color of the nacre and the mantle tissue, but also on the color of the donor tissue that is grafted into the oyster. Different donor tissues can cause the pearl to have lavender, green, blue and ‘peacock’ overtones. These types of pearls are highly prized for their luster and iridescence.
Even though cultured and natural pearls come in a wide variety of colors, pearls are sometimes dyed. A lot of times, freshwater and akoya pearls are dyed dark colors to give them the appearance of a Tahitian or South Sea pearl. The dyes are organic and don’t harm the stone but it is important to be aware of this when shopping for pearls. If a pearl looks too beautiful to be true, it may be! You can spot a dyed pearl by looking down the drill hole with a magnifier. Even the color of Tahitian pearls can be tampered with. Sometimes heat is used to alter their color and achieve a chocolate color which has become very popular in the jewelry world.
