This is a very important question. Pearls are not as hard as most gems. They can be damaged.
Cleopatra supposedly mixed a pearl into vinegar that dissolved the and drank it down. And, I have seen pictures of partially dissolved pearls that a dog had swallowed, and gastric acids ate half of the pearl.
However, certain historic pearls that are several hundred years old and have retained their beauty, and that there are pearls that are 60 million years old and still have good luster.
With proper care pearls can and do last a long time. I am sure most people have seen heirloom pearls passed down from generation to generation.
• Pearls are relatively soft. They can scratch. Best to store pearls in a soft cloth bag away from other jewelry.
• Pearls are somewhat porous. Your pearl necklace can absorb the cologne sprayed directly on it. And the damage may not be limited to the pearls absorbing smell.
• Pearls do benefit from humidity. Pearl jewelry is affected by very dry conditions. Dry conditions have been known to shrink and crack pearls. Best bet? Sprinkle that cloth bag that you store them in with a few drops of water, and put in a zip-lock bag or store pearls in a container with a glass of water.
• Have your pearl necklace or pearl bracelet restrung every 2 to 3 years. A qualified professional stringer will use good quality silk, and knot 1 or 2 knots between pearls. You can imagine what happens to a strand of pearls that is strung with no knots, when the string breaks, no fun at all. Plus the knots keep the pearls from rubbing.
• Please treat your pearl bracelet and pearl ring with care, take them off when washing dishes.
• And although your looks exquisite against your beautiful tan, do take them off before going in the pool. Chlorine and bleach damage pearls.
• Acid will harm those beauties. And lemon juice is an acid strong enough to do damage.