The 44-foot-long Lafoes Carpet is valued at $800,000 to $1.2 million. (t/Corcoran Gallery of Art)

The intricately woven carpet of red and blue and green, with its asymmetrical pattern of sickle-shaped leaves and floral profusion, was created by an unknown artist in Persia, for someone important, possibly the shah, in the first half of the 1600s to decorate the dais of his throne.

Later, it fell into the hands of a dealer in Paris, where a blustery billionaire industrialist-turned-senator from Montana fancied it. William Clark probably hung it on the wall of his Fifth Avenue mansion in New York in the early 1900s. Upon his death in 1925, his will bequeathed the rug, with his other art, to the Corcoran Gallery of Art. Highly acclaimed — yet rarely seen except in art books — the carpet spent most of the next 88 years in delicate storage.

Now the so-called Clark Sickle-Leaf Carpet is valued at $5 million to $7 million, and it is the showy star of 25 fine rugs and carpets that the Corcoran is offering for auction June 5 with Sotheby’s in New York. The auction house calls the Sickle-Leaf “one of the most iconic and important carpets ever to appear at auction.”

“It’s a carpet that has always been revered by carpet people,” said Mary Jo Otsea, senior consultant for rugs and carpets at Sotheby’s. Yet, “It’s one of those beautiful works that really transcends categories.”

The Corcoran is expected to reap at least $6.7 million at auction, the tally of the estimated minimum value of the 25 pieces.

The Clark Sickle-Leaf Carpet could sell at auction for as much as $7 million, and it is the flashy star of the auction of 25 fine rugs and carpets the Corcoran Gallery of Art is auctioning. (Corcoran Gallery of Art)

All proceeds will be dedicated to acquiring works that better fit the gallery’s focus on American and contemporary art, said Harry Hopper, chairman of the Corcoran’s board of trustees. The money will not be diverted to operating expenses or other purposes at the financially struggling gallery, said Hopper, citing the Corcoran’s deaccession policy, which adheres to accepted museum standards.

“The deaccession and sale of these carpets will keep alive Sen. Clark’s generous legacy by enabling us to grow our core collections and make dynamic acquisition choices,” Philip Brookman, chief curator and head of research at the Corcoran, said in a statement.

Clark’s original bequest included 200 paintings and drawings, and numerous other types of work, including rugs, a favored acquisition of industrialists at the time. The bequest expanded the scope of the Corcoran’s collection so much that his widow and daughters — including the mysterious Huguette Clark, who died in 2011 — financed the Clark wing to display a fraction of it. But Clark’s omnivorous artistic taste didn’t mesh easily with a coherent museum collection.

The timing of the auction announcement is only indirectly related to the Corcoran’s ongoing effort to craft a plan to make the institution financially viable, Hopper said. Corcoran trustees are meeting weekly to fulfill a self-imposed deadline of sometime in March to unveil a new vision for the gallery and the Corcoran College of Art and Design.

“We’re looking at everything we can do to make the institution more vibrant, and having funds for new works is one element of that,” Hopper said.

The Corcoran, like many museums, often deaccessions redundant or off-topic works, including 15 rugs in 2009, said Hopper, who noted William Clark’s descendants have supported sales.

The auction will be a significant event in the world of rug collectors, especially with the presence of the Clark Sickle-Leaf Carpet, Otsea said. Buyers will probably dial in from the Middle East, Asia, Europe and the United States — plus live bidders in New York. That was the case when Sotheby’s recently sold a 17th-century Persian carpet for nearly $2 million, Otsea said.

Other choice rugs for sale include the Lafoes Carpet (44 feet long), which Clark put on the floor of his painting gallery in his Fifth Avenue mansion; it is valued at $800,000 to $1.2 million. A circular Ottoman Cairene carpet that belonged to an Italian duke before Clark acquired it is valued at $80,000 to $120,000.

But the Sickle-Leaf surpasses the rest in value and excellence. It is about 8 feet, 4 inches by 6 feet, 3 inches. The warp is beige cotton and the weft is red silk. In a 2001 catalogue, Corcoran curator Laura Coyle compared it to “a bird’s eye view of a wooded landscape.”

It is distinguished for its crispness of imagery and vibrancy of colors, Otsea said. The work gained international renown in a seminal 1939 study of Persian art.

With the exception of a few shows, including in 2003 at the Sackler Gallery, the rug has rarely been appreciated in public. The Corcoran displayed it infrequently, in part because it didn’t exactly belong with the museum’s other work, and in part to protect it.

Otsea called it a career highlight to work with the Sickle-Leaf Carpet. “I’ve been looking at carpets for 30 years, and I’ve loved this carpet for 30 years,” she said.

Those with neither the cash to buy a rug, nor a gallery in which to display it, can see the 25 pieces on exhibit starting June 1 at Sotheby’s, 1334 York Ave., New York.