A pearl is formed when an irritant or parasite penetrates and lodges in the mantle tissue of a mollusc. In response, the mollusc secretes a substance called nacre, and the creation of a pearl begins. Nacre is a combination of crystalline and organic substances. The nacre builds up in layers, as it surrounds the irritant to protect the mollusc, and after a few years, this build up of nacre forms a pearl. Natural pearls, are pearls formed by chance. Cultured pearls have been given a helping hand by man. Today, nearly all pearls are cultured. By inserting a foreign object into a mollusc, pearl farmers can induce the creation of a pearl. From there, the same process of natural pearl creation takes place. The difference is that in this case, the inducement is intentional. Cultured pearls can be distinguished from natural pearls through the use of x-rays, which reveal the inner part of the pearl. For more information on cultured pearls please visit:- http://www.pearl-guide.com/cultured-pearls.shtml | 
