Why Some Pearl Necklaces May Not Last

Feb. 12 -- Lately, pearl jewelry is becoming a hot fashion accessory, with pearl-sporting stars like actress Sarah Jessica Parker contributing to the sizzle.

But if you buy a string of cultured pearls at some national jewelry store chains, they might not last as long as you think, one jewelry expert told Greg Hunter, consumer correspondent for ABCNEWS' Good Morning America.

"It will change, it will deteriorate into worthless shell beads because the pearl coating basically comes off," said Antoinette Matlins, a gem and jewelry expert and author of The Pearl Book: The Definitive Buying Guide. "It won't be a pearl."

As an experiment, Matlins and a Good Morning America producer went pearl shopping at three jewelry stores that were part of national chains, and one department store. After expert gemologists examined the brand-new jewelry, they found three of the necklaces and one of the bracelets had pearls that were already chipping around the drill holes, where the pearls are strung together.

"Oh my goodness ... this is absurd," said Cap Beesley, president of American Gemological Laboratories in New York, who examined a pearl necklace that they had purchased for $464. The store, part of a national jewelry chain, had marked it down from $999.

When Beesley looked at the necklace under a microscope, the gemologist found several chipping pearls, which seemed to be missing large sections of nacre, the natural substance that from which pearls are made.

Pearls Are Big Business

Most pearls sold today are not the natural kind, but rather cultured pearls, grown on pearl farms.

Natural pearls form when an irritant — such as a grain of sand — gets into an oyster, prompting it to produce nacre, a coating substance that eventually forms a pearl. Such natural pearls are rarely found; the fine ones that do exist command staggering prices and are mostly owned by collectors or connoisseurs.

Since pearl cultivation started in earnest back in 1920, pearl farmers have been giving nature a little push to create pearls the same way that natural pearls form.