natural v. cultured pearls

A natural pearl will occur without any human intervention. These days the most beautiful pearls in the world are cultured or cultivated pearls. In a natural state, only a very small percentage of oysters will ever produce a pearl. A cultured pearl, by contrast, is artificially produced. This technique involves the deliberate insertion of a foreign substance called nucleus into the tissue of the oyster or mollusk. After the implanting procedure , the mollusk is returned to the water for its cultivation period. Over a period of time the nucleus gradually becomes coated with layers of nacre that form the pearl.