A natural pearl is created, as the name implies, by nature.
All pearls grow around a core.
The core of a natural pearl is simply a fragment of shell or fishbone, or a grain of sand that strayed into the unsuspecting pearl oyster s shell. All this happens quite by accident or on the whim of nature. A cultured pearl is also grown by nature but with the assistance of man. In 1893, Kokichi Mikimoto discovered a way to duplicate this process of nature and not have to depend on fate to begin the process of growing these beautiful pearls. Eventually, he would develop and patent a process that would produce perfectly spherical cultured pearls.