Pearls

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Pearls

Natural Pearls - a natural pearl forms when a parasite or some other foreign matter enters the body of a pearl-producing mollusk. The mollusk deposits layers of nacre over it to soothe the irritation. Natural pearl are very rare in today's market, and can usually only be found in estate jewelry.

Cultured Pearl - cultured pearls are formed the same way natural pearls are formed except man inserts the foreign matter into the mollusks shell. There are 2 kinds of cultured pearl on the market today, Saltwater, and Fresh water.

Salt Water Cultured Pearls form when a bead nucleus and a piece of mantle tissue are inserted into the mullosk. The mullusk first deposits a layer of conchiolin (simalar to the material found in hair and finger nails) over the bead nucleus. Then it deposits nacre, which is composed of platelets of aragonite. This process is called bead nucleation.

For Fresh Water Cultured Pearls the typical culturing process starts when a piece of mantale tissue is inserted into a mussel. Although a bead isn't inserted, the host mollusk reactes to the intruding tissue the same way as in bead nucleation. It secretes a layer of conchiolin, then layers of nacre. This process is called tissue nucleation. Tissue nucleated pearl are almost entirely nacre.

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Akoya - the saltwater pearl are cultivated in Japan and China in a mollusk know as the Pinctada fucata, more commonly called the "akoya oyster". These pearl have a typical size rangefrom 6mm to 7mm. They have a white to cream boday color and are the most common pearls in today's market.

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South Sea - these pearls are commonly cultivated in Australia, Indonesia, and the Philippines. They are formed in the Pinctada maxima mollusk or the "silver lipped and golden lipped oysters". These pearls range in color from white to golden and tipically range in size from 8mm to 15mm.

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Tahitain - Cultivated primarily around the islands of French Polynesia these pearls are cultivated in the Pinctada margaritifera or the "black lipped oyster". They rancg in size from 8mm to 14mm and have a color range from white to black,to some other colors including green and purple.

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Freshwater pearls - these pearls are found in a large range of colors, sizes and shapes. China is the major source for freshwater pearls, however Japan and the US produce some. Fresh water mussels that produce these pearls include Cristaria plicata or the "wrinkle or river shell", found in the rivers and lakes of China, Japan, and Vietnam, Hyriopsis cumingi or "triangle shell" found in China, and Megalonaias nervosa or "washboard" originally used to culture pearls in North America, today virtually all are produced in M.nervosa.

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Keshi - these pearls are accidental byproducts of salt water and fresh water processes. Generally irregular in shape they come in a variety of sizes and colors.

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Blister - these pearl grow atatched to the mollusk's shell, one side is flat and without nacre.

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Mabe - these are assembled blister pearls. They are cut from the shell and have a mother of pearl backing glued on.