5 tips for keeping precious pearls clean

Pearls are as sensitive as they are beautiful. Perfume, cosmetics and hairspray can stain them; the acids in your perspiration can eat away at their fine coating and since a pearl's value is largely determined by its colour, lustre and coating thickness, cleaning is essential for maintaining their value.

• Wipe off your pearls after each wearing.
• Use a barely damp, very soft cloth — chamois is best. This removes harmful substances such as perspiration, perfume and make-up that can penetrate the pearls' porous surface.
• As a preventive measure, always apply perfume, make-up and hair spray before you put on your pearls.

• Occasionally clean your pearls more thoroughly to restore their natural finish and lustre.
• Use a mild bar soap and lukewarm water to create light suds.
• Dip a soft cloth into the suds and gently wipe the pearls.
• Rinse with clean water and then dry with another soft cloth.
• Never soak pearls because that will get the string too wet and weaken it.

• To make sure the pearls and string are dry, lay them on a slightly damp cloth. When the cloth is dry, the pearls will be, too.
• If you wear pearls when their string is wet, the string might stretch and attract hard-to-remove dirt.
• Never hang pearls to dry, since that might also stretch the string.

• To remove stubborn lumps of dirt, use your fingernail, which has a hardness of 2.5 or less on the Mohs' scale (a scale of mineral hardness on which 1 represents the hardness of talc and 10 represents diamond).
• Pearls have a hardness of 2.5 to 4.5, which means your fingernail probably won't scratch them, but proceed with caution anyway.
• Keep in mind that, as mentioned earlier, pearls are quite sensitive, so treat them accordingly and they'll look good for years.

Pearls can be harmed by many common cleaning substances and methods, including ammonia, commercial jewelry cleansers that contain ammonia, ultrasonic cleaners, steam cleaners, detergents, bleaches, bicarbonate of soda, powdered cleansers, vinegar, lemon juice and most dishwashing liquids.