The cultured pearl is basically a 20th-Century product.- Diamonds, Gems

	Home Page \| Jewelry Metal

Cultured Pearls

The cultured pearl is basically a 20th-Century product. Several men tried to develop a method for producing spherical pearls, and the name¬ Nishikawa, Mise, and Mikimoto are prominent in this regard. After . complicated patent settlement, Mikimoto emerged dominant in the cultured pearl industry.

A cultured pearl is produced by inserting a mother-of-pearl be& into the tissues of a pearl-producing mollusk. The mollusk treats the bead as an irritant and deposits a nacreous coating over it. Thus, the basic difference between a natural and a cultured pearl is the nature and size of the nucleus particle, and the way the pearl originates.

Blister pearls are produced by inserting a half-bead against the shell of the mollusk. After a layer of nacre has been deposited over the bead the whole formation is cut out and the nacreous dome cemented onto, mother-of-pearl bead. The result is called a mabe pearl.

Cultured Pearls

Biwa pearls are produced at Lake Biwa, Japan using freshwater clams. Biwa pearls are irregular in shape, but have good color an, orient. They are distinctive because they have no nucleus; instead of ,¬bead, small squares of tissue are inserted into the clam. The pearls that develop require three years to grow.

Japan is the world's leading producer of cultured pearls. The usual shapes produced are the baroque, round, button, oval, pear, and egg very few cultured pearls are perfect spheres. Of all gems, pearls are the most difficult to authenticate.

The only truly reliable test involves the us( of an x-ray machine, which can be dangerous in unskilled hands. Fin( cultured pearls are, to the eye, indistinguishable from genuine pearls and simple tests are not reliable in all cases.

The qualities that determine the value of genuine pearls also apply in the case of cultured pearls. Generally prices of cultured pearls arc lower, but even a strand of these may bring a price in excess of $100,000.