Avoid commercial jewelry cleaners on pearls unless specifically recommended for pearl cleaning. Many commercial cleaners contain ammonia, which will cause deterioration. Vinegar will also deteriorate pearls if not rinsed off right away. Never clean pearls in an ultrasonic cleaners which can damage pearls.
Hairspray, perfumes, and cosmetics can disintegrate the pearl's surface, so should always be used prior to putting on your pearl jewelry.
To clean pearls avoid abrasive powdered cleaners, baking soda, toothbrushes, scouring pads, or materials that can damage the pearls surface. Gently rub pearls with a soft cloth to remove caked-on dirt, body oils, and perspiration (which is acidic) and harmful to a pearl's surface and color. Cloth may be dampened if necessary.
Store your pearl jewelry in a soft jewelry bag, or wrap your jewelry in a linen handkerchief to protect it from scratches and damage.
Avoid storing pearls in sealed plastic bags or excessively dry places which can cause your pearls to crack. Pearls are composed of approx. 2 to 4% water along with calcium carbonate and organic binder called conchiolin. Storing pearls near a heater or places exposed to strong sunlight results in dehydration and causes pearls to become brittle and crack.
Remove pearls before performing strenuous exercise or work that could result in damage to pearl jewelry.
Restring pearls periodically. When excessive wear is noticeable once a year is recommended. For your very fine pearls it is recommended pearls be silk knotted between each pearl to prevent damage from pearls rubbing against each other, or getting lost if silk cord breaks.
If pearls are excessively dirty they can be cleaned by a jeweler or they can be washed in a sudsy water with a mild liquid soap such as Ivory or Lux liquid soap (not a detergent). Pay close attention to the areas around the drill holes where the dirt collects. Lay pearls flat on a moist wash cloth to dry after washing. When the wash cloth is dry the pearl strand should be dry. To prevent silk cord from stretching do not wear pearls wet, or hang pearls to dry.
Pearl are an organic gem, created when an oyster covers a foreign object with beautiful layers of nacre. Long ago, pearls were important financial assets, comparable in price to real estate, as thousands of oysters had to be searched for only one pearl. They were rare because they were created only by chance. Today pearl are cultured by man: shell beads are placed inside an oyster and the oyster is returned to the water. When the pearl are later harvested, the oyster has covered the bead with layers of nacre. Most cultured pearl are produced in Japan. In the warmer waters of the South Pacific, larger oysters produce South Sea cultured pearl and Tahitian black cultured pearl, which are larger in size. Freshwater pearl are cultured in freshwater mussels, mostly in China. The quality of pearl is judged by the orient, which is the soft iridescence caused by the refraction of light by the layers of nacre, and luster, the reflectivity and shine of the surface. Fine pearl do not have any flaws or spots in the nacre: it has an even smooth texture. Other factors which affect value are the regularity of the shape, size, and color: rose tints are the most favored. Cultured pearls and natural pearls can be distinguished from imitation pearls by a very simple test. Take the pearl and rub it (gently!) against the edge of a tooth. Cultured and natural pearls will feel slightly rough, like fine sandpaper, because of the texture of natural nacre. Imitations will feel as smooth as glass because the surface is molded or painted on a smooth bead.