Virtually all pearls available today are cultured. The pearl culturing process begins when a skilled technician surgically implants a shell bead or piece of mantle tissue into a host oyster or mussel to induce the creation of a pearl. From this point, the same process of natural pearl creation begins. The oyster or mussel secretes a crystalline substance, called nacre, which builds up in layers over time. This creates a surface that glows with a lustre unique to true pearls. Artificial, or imitation, pearls, on the other hand, do not involve oysters or mussels in any way, and are manufactured from various chemicals and compounds. PacificPearls.com sells only real pearls that are created by living oysters and mussels.