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                | Natural 
                  but cultivated pearl produced by a mollusk after the intentional 
                  introduction of a foreign object inside the creature's shell. 
                  The discovery that such pearls could be cultivated in freshwater 
                  mussels is said to have been made in 13th-century China, and 
                  the Chinese have been adept for hundreds of years at cultivating 
                  pearls by opening the mussel's shell and inserting into it small 
                  pellets of mud or tiny bosses of wood, bone, or metal and returning 
                  the mussel to its bed for about three years to await the maturation 
                  of a pearl formation.  | 
               
             
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