Since cultured pearls are relatively soft compared with other gemstones and precious metals, it is important to take special care of your pearls so that they stay bright and beautiful for generations to come. Cosmetics, perfumes and hair sprays all contain chemicals that can dull the luster of pearls when exposed over extended periods of time. Acids in body oils and perspiration can also damage pearls' luster in the same way. Henceforth, it is better to wear your pearls after applying makeup, perfume or hair spray. By the same token, you should wipe your pearls after each wear with a soft damp cloth to remove any harmful build-ups. Occasional washing is also recommended. Jane’s Pearl World suggests using an unused makeup brush, and clean your pearls with warm, soapy water. Afterwards, simply lay the pearls on a towel to dry. The wet string can stretch—and attract dirt, so don’t touch a string of pearls until they are completely dry. Pearls worn every few days should be restrung once a year. Also, pearls should always be stored in separation from hard jewelry item(s), such as metals and other gemstones, to prevent scratches. It is best to keep pearls in a soft cloth pouch or a separately lined jewelry box. If you plan to wear your pearls several times a week, we recommend that you take the pearls to your jeweler for an annual re-stringing to avoid breakage. The strand must be knotted between every two pearls, both to prevent the pearls from rubbing against each other, and to save them from falling at once, should breakages were to occur. With proper attention and handling, pearls will last for eternity. But if continuously exposed to harmful products -- such as cosmetics or abrasive detergents, pearls' luster can diminish over time. As a result, light cleaning with a soft, damp cloth after each wear is recommended, along with periodic deep cleaning by a professional pearls business.
Luster is the amount of light reflected on the pearl surface. In other words, luster is the surface glow, as well as the deep mirror-like reflection of the light, or the inner light. Nacre quality in cultured pearls will improve the overall luster. Many even layers of nacre are required to create a highly defined spectrum of color.
As a product of nature, tiny marks found on pearls are part of their natural texture and are proof of the genuineness of a cultured pearl. These blemishes are formed by outside sea particles and objects that find their way into the oyster and brush against the pearl. A pearl is considered most valuable when the surface imperfections are minimal.
Perfectly round pearls are the rarest and most valuable. Button pearls are round on one side and flat on the opposite end. Other shapes like tear drop and baroque are also favored because of their uniqueness. A pearl takes its unique shape when an outside entity attaches itself to the forming pearl and it is covered by nacre layers.
It is easier to distinguish imitation pearls from cultured pearls.
Imitation pearls are manufactured to simulate both saltwater and freshwater pearls. They typically are made of glass, plastic, wax, or shell, and are coated with various products to mimic the appearance of cultured pearls. Standard gemological testing and observations should separate an imitation pearl from a cultured pearl.
Cultured pearls are carbonates, so they will exhibit birefringence (a carbonate blink) in the refractometer. Glass, plastic and wax are amorphous and will not show birefringence.
Look down the drill hole using 10x magnification and strong lighting. An imitation pearl may not show a separation between the glass nucleus and the coating. Also, the drill hole may show the ragged edges of the coating rather than the sharp, well-defined edges of a cultured pearl.
Magnification At 50x magnification, the surface of a cultured pearl typically reveals recessed, step-like depressions and overlapping lines of nacre that look like sutures, while the texture of imitation pearls may look even and smooth.
You can also apply the “tooth test”. The nacreous surface on a cultured pearl is uneven, it feels gritty or rough when rubbed gently on the biting edge of your front teeth. The surface of an imitation pearl feels smooth by the same test.
Please note that the tooth test should be done discreetly and does not provide absolute proof of a pearl’s authenticity.