Pearl is the oldest valued gem, but unlike other gems, it is derived from living organisms such as mollusks- the oyster. This hard and ideally round and smooth object is naturally produced and is cultivated or harvested. It is composed of calcium carbonate in tiny crystalline form, which has been deposited in concentric layers.
For centuries, pearl is regarded for beauty and value. It is used in jewelry and ornaments specifically on bridal gowns or worn as jewelry by the bride, as well as is crushed in cosmetics or paint formulations. The word pearl has become a symbol of purity and innocence, so as to figuratively refer to something rare, fine, and admirable.
Pearls can be saltwater pearl or freshwater pearl. Saltwater pearls are produced within oysters in tropical oceans. Freshwater pearls are produced from species of freshwater mussels (Unionidae).
Pearl is produced naturally or is cultured. Natural pearls are formed by nature without human intervention. Pearls are produced as a response to an irritant inside the shell of certain bivalve organism to seal off the irritation. Some organic material, parasites, or even damage that displaces mantle tissue to another part of the animal's body. The calcium carbonate (CaCO3) in the form of the minerals aragonite or calcite (both crystalline forms of calcium carbonate) that are deposited by the mantle of the bivalve organism that combines with conchiolin produces nacre (mother-of-pearl). These pearls are almost 100% nacre. In the creation of cultured pearls on the other hand, the bivalve organism is irritated with a cut piece of the mantle epithelium, together with processed shell beads.
Philippines now produce the best golden pearls grown anywhere. South Seas pearl specialist Alex Vock of ProVockative Gems in New York said that, “The Philippines have made enormous strides both from a standpoint of quality and quantity in the last five years.” About 70 percent of the country’s production of pearl comes from Palawan.
The value of pearl depends on its physical properties such as size, shape, quality of surface, orientation, and luster. Often pearls are white or cream, but it varies according to the color of the nacre in the various species of mollusk. It can also be black, or various pastel shades. Pearls can also be dyed. The Philippines' most native oysters are of the yellow-lipped variety more suited for growing pearls with cream and golden colors. Thus, to produce large pearls of whiter, more silver-lipped oysters, and pearls with cooler hues for fairer skin types, Philippine farmers of pearl have used biotechnology, outpacing Indonesia’s production. According to American jeweler, Philippine cream-roses, cream-whites, and assorted yellows and golds will become increasingly sought-after shades. Philippine production's shapes is 50 to 60 percent round, semi-round, and drop shape, with the remainder semi-baroque to baroque. The average pearl size is 12mm to 9mm. The Philippines outpaces Japanese pearls with 1mm nacre thickness against 3mm.
- "Philippine Pearls." Modern Jeweler. http://www.modernjeweler.com/online/article.jsp?siteSection=3&id=257&pageNum=1 (accessed on 16 January 2008)
- "Pearl gemstone meaning." Emily Gems. http://crystal-cure.com/pearl.html (accessed on 16 January 2008)