Pearls are sometimes referred to as the world’s most colorful gem, a title they have certainly earned! Rivaled only by garnets, which are available in every color of the rainbow, pearls are known for the amazing colors they display. However, not all of these colors occur naturally. There are many treatments that are considered acceptable in the jewelry trade to enhance the color and luster of the pearls in question. At Pearls International, we offer many color enhanced freshwater pearls so that you can find a color and style that suits your own personal flair. Note that when these treatments are done correctly, they do not detract from the value of the pearl. Here are the main treatments used to prepare pearls for use in jewelry:
Polishing: While it is is not necessary to cut a pearl or polish it in the manner you think of with other gemstones, they still have their own polishing procedure they are subjected to before being drilled and prepared to sell. They are simply tumbled in a salt water solution that is just course enough to remove any build up or organic matter from the pearls. This process can also sometimes remove small surface imperfections.
Maeshori: This is a process that originated in Japanese pearl farms, meaning “Before Treatment.” It refers to a range of treatments done at the farms, including polishing. When you hear of maeshori today, it means the process by which the pearl has been heated and then cooled in order to “tighten” up the nacre´ (smooth Mother-of-Pearl substance that forms the pearl) which causes the pearl to show increased luster. This process is comparable to a person getting a facelift.
Bleaching: Many freshwater and saltwater pearls are bleached to improve the color of white pearls. Bleaching also evens out some surface flaws. A natural color white strand will show slight variances in the hues of each pearl, while a bleached strand will appear very uniform. Pearl bleaching has been practiced for over 100 years and is considered an industry standard in production of white pearls.
Dyeing: Fancy color pearls such as cranberry and bright blue or green pearls have been treated with an organic dye. Sometimes freshwater pearls are dyed to mimic the color of saltwater pearls at a much lower price. Black freshwater pearls, for example, are dyed to look like Tahitian pearls. The same is true for chocolate color freshwater pearls. Chocolate Tahitian pearls are few and far between as it is, so it is a highly desired color based on rarity. Sometimes Tahitian pearls are dyed brown to make a matched chocolate Tahitian strand, without the pearl farmers having to wait the several years it would take to create a full strand of naturally chocolate color pearls. Dyeing a pearl does not detract from the value of the jewelry as long as it is done well. If you can see blotchiness on the surface of the pearl, or if you can see the original white color around and inside of the drill hole in the pearl, it has been poorly dyed. The color should be smooth and even across the surface of the pearl. Another common practice, related to dyeing, is called “pinking” which is most commonly done on Akoya pearls to increase the rosey overtones in the nacre´. This is achieved by soaking the pearls in a diluted red dye.
Irradiation: This is a treatment most commonly applied to saltwater pearls. It is rarely seen in freshwater pearls, because the cost of this treatment usually outweighs the value. The pearl is subjected to gamma rays, which darkens the pearl. In the case of saltwater pearls, it darkens the shell bead nucleus (which is made from a freshwater mussel). Because the center of the pearl has been darkened, the layers of nacre´ covering the pearl appear darker because of how the light refracts on the surface of the pearl, allowing you to see the nucleus underneath. The thicker the layers of nacre´ (so, the larger the pearl) the harder it is to see. Saltwater pearls treated in this manner will usually become silvery or gunmetal grey in color, not black. Freshwater pearls treated with irradiation will become very dark and it is a good way to get black freshwater pearls with high luster. It’s important to note that these pearls are not radioactive, and therefore are completely safe to wear and enjoy.
There are a couple of other treatments that some pearl farms may choose to do, but these are the most common and most acceptable in the pearl industry.
So, how can you tell if your pearls are a natural color or an enhanced color? Certain types of pearls are available in a range of natural colors. All others not listed are dyed or otherwise enhanced for fashion.
Akoya Pearls: Japanese Akoya pearls are one of the most popular pearl types on the market, and are the most obtainable saltwater pearls. They come in white and cream, with rose, silver, or gold overtones. They are also sometimes seen in a stunning silver-blue color, although these are very rare.
South Sea Pearls: These rare treasures are available in white and gold, with the darkest golden pearls being considered the most valuable.
Tahitian Pearls: One of the most sought after saltwater varieties of pearls, Tahitian pearls are prized for their dark color and ‘peacock’ overtones, although they can occasionally be found in chocolate as well. Most Tahitian pearls lean towards silver or grey rather than true “black.” (As in jet black, which is an unnatural color.) Pinctada margaritifera, the oyster that produces these gorgeous pearls, also produces their cousin, Fiji Pearls. Fiji Pearls are truly the most colorful pearl in the world, and one of the rarest. Because the waters they are farmed in are so nutrient-dense, they come in a rainbow of colors including the traditional blacks and greys, as well as bronze and gold.
Sea of Cortez Pearls: As only one pearl farm is currently culturing these pearls, Sea of Cortez pearls are the most rare. They are also never enhanced to improve their color, so you know that if you purchase a Sea of Cortez pearl, it is unaltered by man once it leaves the oyster. Their colors are similar to those shown in black peacock Tahitian pearls, although they are somewhat more bold and rich in color than the Tahitians are.
PS – You can click here to read more about the amazing Sea of Cortez and Tahitian black peacock pearls mentioned above!
Freshwater Pearls: Making up the bulk of the pearl market, most pearls you will come across while pearl shopping are freshwater. They take the least amount of time and effort from the pearl farmers to produce, and are cultured in several places around the world from a few different species of freshwater clams. These pearls naturally come in white and cream, as well as pastel colors such as peach, lavender, and pink. Any unusually dark or very brightly colored freshwater pearls are typically dyed.
When in doubt, a reputable company should always be honest with you about the jewelry you are buying – just ask!