Pearls are one of the oldest used gem by man. Natural pearls are found in the body of mollusk which are formed by the layer upon layer secretion of nacre (a secrete from the mollusk) as a defensive mechanism towards foreign object such as sand which get into it’s body.
Natural pearls are one of the high valued gemstones and are extremely rare, most of the pearls found today are cultured pearls. Pearls can be broadly classified into freshwater pearls and salt water pearls.The different kinds of pearls include akoya pearls, Tahitian pearls, south seas pearls, white pearls, keshi pearls etc. Akoya,Tahitian and south sea are the varieties of saltwater pearls. In jewellers terms,saltwater pearls are referred as oriental pearls which are often more valuable than the freshwater pearls, although quality freshwater pearls can be exceedingly valuable.
Pearls are appraised by their shape, surface smoothness, translucence, delicate play of surface called ‘orient’ and the light reflective quality termed as ‘lustre’. Pearls come in shapes like round, oval, pear-shaped and even irregular. The most valued pearls are usually the perfect shaped pearls such as spherical or drop like. Lustre also influences the value of the pearl, deeper the lustre of the pearl, greater is its value.Quality of nacre is what gives high lustre to the pearl and will be evident to the naked eye as a shiny pearl.
There isn’t an industry accepted grading system for pearls. Pearl grading system varies from place to place. Various grading standards for pearls exist around the globe like Japanese Grading (Mikimoto Grading), Chinese Grading System and Kyllonen Grading System etc., unfortunately there is no universally accepted standard. However, for Tahitian pearls, export and grading is controlled by the French Polynesian government. The variables to compare the quality of a pearl are basically the same in all grading systems but the terminologies varies.
Pearl is an organic gemstone. Pearls are tough but ageing, dehydration and chemical reactions can make it fragile. Pearls are sensitive to acids, alkalies, excessive temperature, humidity etc. Since pearls are chemically vulnerable, it is better to avoid direct contact with cosmetics. Chemicals from cosmetics can easily dull the lustre of pearls. Wipe the pearl clean for storage using a lint-free cloth after each use.
Keep the pearl jewellery in separate jewellery case or pouch for storage. Pearls are relatively softer compared to other gemstones. Never leave the pearl jewellery along with other jewellery items as pearls can get scratched easily with sharp edges of metals and other gem stones.