LONDON — As treasure-in-the attic stories go, the 18th-century Chinese vase sold at a suburban auction house in outer London on Thursday night will be hard to beat.
The delicate, decorative 16-inch vase started at a not-inconsequential $800,000, but after a half-hour of unexpectedly spirited bidding, the gavel fell at $69.5 million. It was the highest price ever paid at auction for a Chinese antiquity.
Adding in the 20 percent buyer's premium levied by the auction house and Britain's value-added tax, the total came to $85.9 million. Auction insiders said the buyer was from mainland China and bid by telephone.
Of the sellers, the auction house, Bainbridge's, said only that they were a brother and sister who had found the vase "in a dusty attic" when they were clearing out the family home in west London, near Heathrow Airport, after their parents died. The other Chinese knickknacks they found sold for as little as $65.
"They had no idea what they had," said Helen Porter, a spokeswoman for Bainbridge's.
The vase dated from the period of the emperor Qianlong, who reigned from 1735 to 1796, at the height of the Qing dynasty. He vastly expanded China's western territories and left a legacy as a great patron of Chinese arts, including ceramics. Experts who have examined the vase, which bore an imperial seal, have said it was likely to have been made for one of the imperial palaces.
Ovoid in shape and predominantly pastel yellow and sky-blue in color, the vase has a narrow neck, four enameled circular motifs known as cartouches that show colorful fish and flowers, and elaborate perforations in the outer vase that give onto a smaller vase inside. It was believed to have been fired in the imperial potteries in Jingdezhen, in Jiangxi province, west of modern-day Shanghai, which functioned for 1,000 years as the porcelain capital of China.
Porter said the sellers had no knowledge of how the vase came to be in their parents' possession, although they believed it had been in the family since the 1930s.
The vase's price exceeded the record for Chinese antiquities set just last month in Hong Kong, when another Qianlong vase sold for $34.2 million.
For Bainbridge's, the sale price of the vase represented a huge leap, putting the auction house, at least momentarily, in a league with the blue-ribbon art houses like Sotheby's and Christie's, where sales running into the tens of millions of dollars have become almost routine in recent decades. Bainbridge's biggest sale before Thursday was $160,000 for a Ming enamel piece.