Pearls are very soft and need special care. They never should be tossed on top of or next to other gems in a jewelry box. Store them in a jewelry pouch. Some women's skin are more acid than others. If a pearl necklace is regularly worn, as it should be, some of the pearls will constantly be in close contact with the woman's skin on her neck at the shoulder line. Pearl pendants do not always have such constant contact with a woman's skin. The pearls in the necklace will gradually absorb acid from the skin and the acid will slowly eat into the spherical pearl. Over time the pearl will not only lose its luster, but will become barrel-shaped. You can slow this process by wiping the pearls with a soft cloth after wearing them.
Besides being soft, pearls are easily damaged by chemicals like perfume, vinegar and lemon juice. Heat can turn pearls brown or dry them out and make them crack. Dry air can also damage pearls. Most safe deposit vaults have very dry air and can damage pearls.
When taking off a pearl ring, grasp the shank, or metal part, rather than the pearl. This will prevent the pearl from loosening and coming into contact with skin oil on your hand. Because of their delicate nature, special care must be taken when cleaning. Only use jewelry cleaners labeled as safe for pearls. Never use an ultrasonic cleaner. Never steam-clean pearls. Never use (or expose pearls) to dish or wash detergents, bleaches, powdered cleansers, baking soda, or ammonia-based cleaners (like Windex). Never use toothbrushes, scouring pads or abrasive materials to clean pearls. Do not wear pearls when their string is wet. Wet strings stretch and attract dirt, which is hard to remove. Do not hang pearls to dry. Take your pearls off when applying cosmetics, hair spray, and perfume, or when showering or swimming. Avoid wearing pearls with rough fabrics like Shetland wool.
Have your pearls restrung once a year if you wear them often. Cleaning Pearls After you wear pearls, just wipe them off with a soft cloth or chamois, which may be dry or damp. This will prevent dirt from accumulating and keep perspiration, which is slightly acidic, from eating away at the pearl nacre. You can even use a drop of olive oil on the cloth to help maintain their luster. If pearls have not been kept clean and are very dirty, they can be cleaned by your jeweler or they can be cleans using special pearl cleaner. Be careful using other types of jewelry cleaner or soap. Some liquid soaps, such as Dawn, can damage pearls. Pay attention to the areas around the drill holes where dirt may tend to collect. After washing your pearls, lay them flat in a moist kitchen towel to dry. When the towel is dry, your pearls should be dry.
About every six months have a jewelry professional verify that the pearls on your jewelry are securely mounted or that the string is still good. Many jewelers will do this free of charge, and they'll be happy to answer your questions about the care of your jewelry.