When a foreign object such as a grain of sand accidentally gets lodged in an oyster, it is coated with layer upon layer of a smooth, hard crystalline substance known as nacre. After a period of time, this natural process produces the luminescent gem called pearl.
Natural, or Oriental pearls are still cultivated in the Persian Gulf and Indian Ocean. However, most pearls sold today are cultured. The culturing process, now an important industry in Japan, was developed during the first 30 years of the 20th century. The quality of pearls varies dramatically, just like other gemstones. Like most of nature's creations, only a tiny percentage are beautiful enough for use in jewelry.
Qualities of a Pearl
Lustre and nacre thickness: Lustre is a combination of surface brilliance and a deep seated glow. That's why the thickness of the iridescent layers surrounding a pearl's nucleus dramatically effect its lustre. Quality pearl lustre is created by heavy nacre and fine surface polish.
Surface: A clean, smooth, blemish-free surface is preferable and more valuable.
Shape: Perfectly round pearls are the rarest and most valuable. Baroque pearls, which are asymmetrical in shape, can be lustrous and appealing, and often cost less than round pearls.
Color: Cultured pearls come in a spectrum of shades from rose to black and may be created by the oyster or dyed by man. Dyed pearls are far less expensive. Whatever the color, it should appear to emanate from deep within the pearl.
Size: Cultured pearls are measured by millimeters. They can be smaller than one millimeter, as in the case of tiny seed pearls, or as large as twenty millimeters for a big South Sea pearl. As with diamonds, size influences price.
Name of Pearls
Pearls are labeled based on their origin.
AKOYA - Cultured in the islands of Japan, these are considered the most common pearls. Sizes range from 2 to 11 mm.
CHINESE FRESHWATER - Cultivated in mussels in lakes and rivers, these pearls grow in an awesome variety of colors and shapes. These pearls are very affordable.
SOUTH SEA PEARLS - Cultured from the silver or white-lip oyster, primarily in the northern waters of Australia, Indonesia and the Philippines, these pearls grow to exceptional size; 10 to 20 mm. These are highly prized and precious.
TAHITIAN PEARLS - Cultured from the black-lip oyster in the waters of the South Pacific, these pearls come in larger sizes, from 10 to 20 mm, and a variation of colors including black, gray, burgundy, peacock and gold. Mystical and dark, the popularity of Tahitian pearls has surged in recent years, making strands of these pearls one of the most sought-after pieces of jewelry.
