BOSTON, MASS. — Eleven phone bidders competed for a signed Van Cleef & Arpels platinum and diamond riviere necklace at Grogan And Company March 20. It opened at $50,000 and quickly surpassed the high estimate of $100,000.

By the time the bidding ended, it cost its new owner $256,200. The necklace had 40 diamonds and the platinum clasp was signed with a hallmark. It had come from the estate of Helene Rabb Cahners-Kaplan, a member of the family that founded Stop & Shop supermarkets.

It was a day for exceeding estimates. A painting of roses by Paul de Longpre (French, 1855–1911), estimated at a high of $5,000 finished at $30,500. Numerous other pieces of jewelry, and several other paintings, sold well over estimates to a full salesroom actively competing with phone bidders and many left bids.

A complete report on the auction will follow.