There was the usual post-sale speculation about who bought what, with Christie’s reporting that a sprinkling of buyers were institutions. Because Gary Tinterow, director of the Museum of Fine Arts, Houston, was the successful bidder on Georges Seurat’s “La Rade de Grandcamp (Le Port de Grandcamp),” which sold for $34 million, many assumed he had bought it for his own museum. Mr. Tinterow, in a telephone interview, said he had bought it for a Houston collector.

The Rockefellers’ place settings and collectibles also brought huge prices, including the 14-karat-gold money clip — depicting Rockefeller Center — which sold for a whopping $75,000 with fees (against an estimate of about $1,200).

“I am surprised at how much more the decorative arts are making than estimate,” Marc Porter, the chairman of Christie’s Americas, said. “I expected some Rockefeller premium, but not the multiples of five and 10.”

Image The “Rockefeller Money Clip,” an openwork gold plaque depicting Rockefeller Center, originally belonged to Laurance Rockefeller and brought $75,000 at auction. Credit... Christie's

Mr. Porter said the $1 billion figure was promoted by the press and not Christie’s. “I never thought it could make a billion dollars,” he said. Speaking of Tuesday night’s $646 million auction of 19th and 20th century art, he said, “You would have to have added another $200 million to that evening sale, which was beyond anyone’s expectation.”

Still, had bidding taken off for the highest-priced lot of the week, “Fillette à la Corbeille Fleurie” (Young Girl With Basket of Flowers), Christie’s might have come close. Instead, the painting sold on one bid to its guarantor for $115 million, with fees. But Mr. Porter said the work was always a gamble, given that it depicts a naked teenage girl and is not easily recognizable as a Picasso.