Physical Properties of Cultured Pearls
The pearl is a small glossy and shiny sphere of calcium carbonate that is formed around a grain of sand by bivalve mollusks or oysters.  A pearl is formed by coating nacreous materials in layers. The oyster deposits several layers of nacre over such a period of years.Both freshwater and marine mollusks produce pearls, but the most valuable pearl oysters originating in the PersianGulf.Â
Known as the mother-of-pearl, the Nacre is composed primarily of crystals which are of a form of a calcium carbonate which is also considered as aragonite. The most highly prized and valued pearls are the ones that perfectly round. Bouton pearls is a term which is sometimes used to define the pearls that have under gone a process of cutting the pearl from the shell which produce a hemisphericalsurface. If a genuine pearl does not have a uniform appearance or has an irregularly shaped, it is much known as a baroque pearl. Pearls are commonly known as drop, pear, or bell, according in particular with its shape. The coloration of the pearlis based on a color continuum ranging from being white, black, red rose, and cream varieties.
River pearls or freshwater pearls are produced in several parts of the globe. China is the principal producer of freshwater pearls. As for marine or salt water cultured pearls, California and Mexico are common areas of production North America. The most renowned are of culture pearl production farms are located in Gulf of Panama, in the West Indies and the islands of the South Pacific, along the coast of India an the rest of South Asia, and on Southeast Asia. As for the Australian marine pearls, these are fished for of the coast of Queensland, Western Australia and in the Torres Strait. |
