Although many mollusks produce pearls, only pearl oysters belonging to the genus Pinctada that live in marine waters are prized for jewelery and have true value.
"Pearl" means any nacreous or other concretion found in various species of bivalve, univalve, marine or freshwater molluscs.
The pearl is a gem of organic origin and produced deep in the waters. It was undoubtedly one of the first to be used by man as ornament and adornment, when he found it within the mollusks he fed.
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