An 84.37-carat white diamond touted by Sotheby's for its size and beauty sold at auction Wednesday to Guess clothing company founder Georges Marciano for just under $16.2 million.

The jewel — the largest top-quality, brilliant-cut white diamond ever to appear at auction — had been valued by Sotheby's at between $13.3 million and $17.8 million.

Marciano's winning bid, made by telephone, came to $16,189,769 including the buyer's premium. It was just short of the all-time auction record for a stone or piece of jewelry, a record held by the same Sotheby's branch in Geneva for a 100.1-carat diamond that fetched $16.5 million in 1995.

"In my 32-year career, this stone ranks among the most beautiful diamonds I have ever seen," said David Bennett, the auction house's chairman of jewelry for Europe and the Middle East. He called it a "magnificent and unique stone."

The diamond has received the highest possible grading, Sotheby's said. It is D-color, or finest white, has flawless clarity, and its cut, polish and symmetry have all been graded excellent, it said.

The New York-based company is hoping the "Magnificent Jewels" sale at Geneva's historic Beau Rivage hotel will help it bounce back from the disheartening results of its Impressionist and Modern Art auction, which sent its stock tumbling.

The sale last week fetched $269.7 million, well short of estimates, and led some analysts to speculate whether the flight from risk currently gripping financial markets may be spilling over into the art world.

The company announced that it lost $14.6 million by purchasing paintings that failed to sell.

The white diamond already has been showcased in Hong Kong, Paris, New York, Rome, Los Angeles, London, Dubai and Bahrain. The auction Wednesday also featured other diamonds, colored stones and gems from the world's leading jewelers.