What is a Cultured Pearl?

Pearls are formed inside the shell of certain molluscs as a defence mechanism. This protects them against a potentially threatening irritant such as a parasite inside its shell, or an attack from outside from injuring the mantle tissue. A cultured pearl is formed with human intervention; an irritant is synthetically positioned within the oyster to replicate this natural process. The irritant; primarily US mussel shell, is typically rounded to improve the probability of the oyster producing a round cultured pearl.