Fresh-water
Pearls
The pearls most of us wear today are cultured
pearls, their existence initiated by humans who insert a
bead or other object into an oyster or clam. The clam coats the
foreigner with nacre, the patina that gives pearls their unique
appearance.
The depth of the nacre coating depends on the type of creature
involved, the water it lives in, and how long the
intruder is left in place before it is removed. As nacre thickness
increases, so does the quality and durability of the pearl.
Caring for Your Pearls
Even cultured pearls with thicker coatings are more fragile than
most other 
gemstones, so you must handle them carefully to keep
them in the bestcondition.Your pearls will stay cleaner if you put
them on after you've applied your makeup and perfume.Be sure to
take off your pearl rings before you apply hand and body creams. Dirty pearls can be cleaned with
a mild soap and water
solution.
Storing Pearls
Don't store your pearls with other jewelry,
because they can be scratched easily when metal or
gemstones rub against them.
