Pearls 101: Natural Pearls
Natural and cultured pearls both come from the same sources and are not artificial. The only difference is that cultured pearls come from mollusks that are bred and tended to by farmers in order to create pearls for harvest. Natural pearls are the result of no intention or assistance by humans, only the phenomenon of the mollusk's normal processes at work.
Before culturing became standard, pearls were discovered haphazardly by those fishing for oysters and other mollusks. Natural pearls are extraordinarily rare; only one in ten thousand oysters will create a pearl on its own.
Almost all natural pearls on the market today are vintage pearls and, due to their rarity, are expensive. If you do have the chance to buy a natural pearl, make certain it comes with an official gemological ex-ray certificate to prove it's natural.