Pearl Formation:Pearls are formed by mollusks that live in bodies of water such as oceans, rivers and lakes, mainly naturally. Pearls begin to form when a stimulus enters the mollusk's shell tissue. In response, the mollusk produces a nacreous layer, which is a thick organic liquid that stays on the stabilizing stimulus for a period of time, resulting in a pearl.

Pearls are hard, rounded products produced by mollusks (mainly oysters), and are produced in three ways

Exogenous, the outer coat membrane of the mussel is stimulated by the invasion of a foreign body (sand, parasites), and the epidermal cells at the site of the stimulus, using the foreign body as a nucleus, become entrapped in the connective tissues of the outer coat membrane, and the entrapped portion of the outer coat membrane epidermal cells divide themselves to form the Pearl capsule, pearl capsule cell secretion pearl quality, layer after layer of the nucleus encapsulated into a pearl. To a foreign body for the nucleus is called "nucleated pearl".

Endogenous factors, the outer epidermis of the outer coat membrane of the clam is pathologically stimulated, part of the cell division and then separated, then encapsulated in its own secretion of organic material, while gradually plunged into the connective tissue of the outer coat membrane, the formation of the pearl capsule and the formation of pearls. Because there is no foreign body as the nucleus, it is called "nucleusless pearl".

Artificial culture with artificial methods, from the pearl mussels coat membrane cut live epithelial cells (referred to as celllets), and mussel shells prepared with the artificial nucleus, implanted with the mussel's coat membrane connective tissue, implanted celllets, relying on the connective tissue to provide nutrients around the artificial nucleus proliferates rapidly, the formation of the pearl capsule, the secretion of nacreous, so as to generate artificial nucleated pearls. Artificial non-nucleated pearls are pearls generated by implanting only small pieces of cells in the outer coat membrane during surgery, forming a pearl capsule through cell proliferation, and secreting nacreous material into the capsule.

Difference between marine pearls and freshwater pearls

1. Shape is different: natural beads in the nucleus of the anomaly is not rolled due to the appearance of the roundness is poor; cultured beads, the general nucleus of the more rounded, so into the beads, there are often fine round beads. 2. Structure is different: cultured beads of the inner core of the artificially produced, the natural beads of the inner core of the natural quartz sand particles or other substances. 3. Natural pearls have no nucleus, the surface is the same, the bead body is tight, delicate, moist, nearly translucent, actually opaque; cultured beads have a nucleus, the surface is not the same, the skin fall is not smooth, there are nested skin, the bead body structure is looser.

4. Different colors: natural beads fine texture, soft luster, high transparency (mostly translucent); raised beads due to the short bead years, loose texture, luster is not strong, the surface is often "small package" commonly known as "Lianzibao" or "grab". "5. natural pearl for the natural formation, particles are not whole, not regular enough, less round, less beautiful shape, less large particles of cultured beads are more neat, more round, more large particles.

6. Natural pearls are formed due to the intrusion of foreign objects, long growth time, its thick texture, skin light is better; cultured pearls for artificial seeding nuclei, short growth time, the pearl layer is thinner, the skin light is poorer.7. Pearls inside and outside of the eye of the hole can be seen inside and outside of the same grain pattern of the annulus, cultured pearls inside and outside of the eye of the hole is not the same, from the eye of the hole look at the division of the two layers, inside and outside of the two layers of the combination of the unnatural.