Freshwater Cultured Pearls
A pearl is created when small piece of a shell or other substance naturally gets inside a clam or oyster. Since it's a foreign substance the oyster creates hardened 'nacre' around it, adding layers upon layers, until it becomes what we know as pearls!
A Freshwater Cultured Pearl is created the same way with help of man. A tiny piece of shell or bead is inserted into the oyster. Then, anywhere from six months to two years, the oyster has created it's pearl!