The Rockefeller grouping forms a kind of Monet variety pack, spanning 1868 to 1917 and offering an overview of his career.
“It’s very rare that you have five masterpieces by one artist in a single collection,” said Adrien Meyer, a co-chairman of the Impressionist and Modern department at Christie’s. “They cover all of Monet’s facets.”
The works include one urban scene, “Extérieur de la Gare Saint-Lazare, Effet de Soleil” (1877), and three water scenes: “Bord de Mer à Sainte-Adresse” (1868), “Camille Assise sur la Plage à Trouville” (1870-71) and “La Seine à Lavacourt” (1879).
The most valuable piece is from Monet’s popular Water Lilies series, “Nymphéas en Fleur” (1914-17). That’s the one the auction house expects to bring the most money: from $50 million to $70 million, Mr. Meyer said, given the track record of similar pictures.
The Rockefellers doted on this picture in particular. “As you were coming down the staircase in the country, there was the Monet Water Lilies,” said Jessica Fertig, a senior Impressionist specialist at Christie’s, referring to the family estate in Pocantico Hills in Westchester County. “It was such a part of their life.”
The art historian Paul Hayes Tucker, a scholar of Impressionism who has written five books on Monet, said that the lineup spoke well of the Rockefellers’ taste.
“It’s elastic, catholic and embracing of all the periods, the real hallmark of enlightened collecting,” he said.
Mr. Tucker said he discovered Monet as a student at Williams College in Massachusetts, where he later taught. Since then, he said the painter “has been my companion, my guide, my soothsayer.”
But only from a distance: He has never owned one of Monet’s works. That privilege is reserved for a lucky few like the Rockefellers and Scott M. Black, the Boston-based founder of the investment firm Delphi Management.
Mr. Black’s collection of more than 50 works includes three Monets, which he has lived with on and off over the years, when they are not on loan to museum exhibitions.
Mr. Black made a fortune picking winners in stocks, which is why his clients include business titans like Michael R. Bloomberg, the former mayor of New York City. And in his estimation, Monet is a consistent performer.
“He didn’t have too many off days,” Mr. Black said. “He’s my favorite single painter of the 19th century.” And he knows the comparables, as they say in the investment game: He owns works by Degas, Renoir, Cassatt and Pissarro.
“There’s such an exuberance on the canvas,” he said. “It’s such a pleasing aesthetic experience.”
Mr. Black bought his first Monet for around $1 million in 1986 — what he now considers a bargain. “It’s worth a lot more now,” he said.