Most cultured freshwater pearls are composed entirely of nacre, just like their natural freshwater and natural saltwater counterparts. Throughout most of this century, the Japanese dominated the ...

Japan's akoya oysters have been preëminent among cultured pearls ever since ... helped open the door for other kinds of pearls, such as Chinese freshwater and South Seas saltwater pearls, with ...

South Sea pearls are the largest cultured-pearl variety ... whereas more common freshwater oysters can take as little as three months and create dozens of pearls. This long cultivation process ...

Pearls are made by marine oysters and freshwater mussels as a natural defence against ... which encases the irritant and protects the mollusc from it. When pearls are cultured commercially an irritant ...