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. 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.
• Do not store your pearls in a safety deposit box. The lack of humidity in a safety deposit box is fine for documents, but may evaporate the moisture content of the pearls and dull the lustre. Pearls that are worn frequently retain their moisture by absorbing it from the air or from the wearer's body. 
• 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.
 

Daily Care

Pearls are organic gemstones that are vulnerable to acid, alkaline and extremes of humidity. To preserve your pearls' radiance, avoid letting them come into contact with cosmetics, hair spray, or perfume. Always put on your jewelry as a final touch, after applying make-up and styling hair.

The pearl's luster can also be harmed by perspiration. To prevent this, before returning your pearls to the jewelry box, wipe them gently with a soft cloth.

Pearl Storage

Pearls are exceptionally cohesive and shock-resistant, but may be scratched by contact with sharp objects or other gemstones. To prevent tangles and scratches, fasten clasps and pins, then lay each item out separately in a compartmentalized jewelry box. When carrying jewelry, use a protective jewelry pouch. Do not store your pearls in a security box for long periods. The lack of humidity may cause pearls to dehydrate, so enjoy them frequently. There is a saying that "pearls want to be worn," and it is true!

Pearl Necklace Lengths and Jewelry Terms

• Choker - About 16". Worn for both formal and casual occasions.
• Princess - About 18". The most popular length, it is a longer version of the choker.
• Matinee - About 22". The usual length for daytime wear.
• Opera - About 30-32". The preferred length for formal wear; often in two strands.
• Rope - About "40" or longer. Configurations include two strands, three strands and knots.
• Clasp - The metal piece that closes the necklace.
• Mikimoto clasps are engraved with the trademark outline of an Akoya oyster enclosing the letter M.
• Knot - Knots tied between each pearl in a necklace prevent pearls from scattering if the string breaks.