By Julia Boorstin

(FORTUNE Magazine) – A FAMOUS, RECENTLY divorced talk-show host wants to dispose of a multicarat diamond engagement ring. A movie star's daughter has a 25-carat pear-shaped diamond lying around. A twentysomething socialite wants to trade in her grandmother's brooch. Selling through an auction house is expensive. And visit a pawn shop? Never! Which is why a growing number of well-heeled women are making SellJewelry the place where the haute go to hawk.

With discreet beige offices in New York City and Chicago (and new outposts planned for Palm Beach, Boston, and San Francisco), four-year-old SellJewelry says it will name a price for any item, and sellers leave with a check averaging $10,000. As one might guess, 75% of customers are women and 65% are over 45. The company then makes its money reselling the baubles to its network of around 20 private collectors and dealers (last year sales hit $20 million).

SellJewelry's biggest asset, however, may be its social connections. Chris Del Gatto, the company's 35-year-old CEO and co-founder, who has worked in the jewelry industry since he was 17, says he became friendly with Evelyn Lauder after supporting her breast cancer charity. He has attracted her socialite set to the company with events like a recent Palm Beach polo tournament. Veronica Hearst's daughter, Fabiola Beracasa, once a SellJewelry customer, is now training as a buyer. The appeal, says one Upper East Side doyenne who had just sold several trinkets from ex-boyfriends, is that SellJewelry is discreet. Del Gatto tells the story of one woman who needed millions to develop a piece of land. "She said she couldn't sell the paintings because people would notice, and she couldn't sell the Bentley, or people would talk, so she sold just under $3 million worth of jewels--and nobody knew." -- Julia Boorstin