HOW A PEARL IS BORN
Oysters and mussels create natural pearls on their own – without the help of human hands. A natural pearl starts out as a foreign object, such as a piece of fishbone or sand, inside the shell.
The oyster or mussel covers the irritant with a secretion of calcium carbonate crystals, known as nacre or mother of pearl, to protect itself. As long as the irritant remains inside the shell, the oyster continues to add layers of crystals to the growing pearl.
Natural pearls are the most valued of all pearl types and include South Sea, Tahitian and Conch pearls. Both South Sea and Tahitian pearls can be cultured as well.
Cultured pearls are made by oysters and mussels with some help from humans. An experienced grafter inserts a nucleus into an oyster or mussel together with a piece of donor mantle tissue, or a graft, and the oyster or mussel begins to form a pearl around the foreign body. These nucleated oysters and mussels are then returned to sheltered, nutrient-rich bays where they grow under careful supervision for up to six years before the pearls are removed.