Pearl facts
There are many types of pearls.
Natural pearls - grown with no help from humans
Cultured pearls - grown when a human intentionally inserts foreign tissue into a living oyster
Fresh water pearls - grow in lakes in mussels
Baroque pearls - irregularly-shaped freshwater pearls
Blister pearls - grown attached to the inside of the shell
Black pearls - vary from gray to black
Pearls are organic gems, created when an oyster covers a foreign object with beautiful layers of nacre. Originally ,the value of one natural pearl was tremendous, because thousands of oysters had to be searched for just one pearl.
Today pearls are cultured by Man. Shell beads are placed inside an oyster, then the oyster is returned to the water. When the pearls are later harvested, the oyster has covered the bead with layers of nacre. This process may take as long as eight years to create a pearl.
Most cultures pearls are produced in Japan in oysters, while freshwater pearls are cultured in mussels, mostly in China.
Cultured and natural pearls can be distinguished from imitation ones 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. Imitations will feel as smooth as glass .
Great care should be taken when cleaning pearls. Use only a very soft cloth.