The building devoted to Islamic art, photographed during construction, occupies the stately 19th century Visconti courtyard. It will open on Sept. 22. (Antoine Mongodin / Musee du Louvre)

The expansion, housed in a shimmering, undulating building, is meant to foster fuller cultural understanding while showcasing beautiful works.

PARIS — The Louvre's astonishing new wing for the department of Islamic art undulates like molten gold, so liquid-smooth in contrast to the surrounding neoclassical architecture framing it that at a glance from afar it almost looks like a digitalized, fake rendering of what visitors can hope to see in the distant future.

For the museum's enlarged, 18,000-piece treasure trove of Islamic art, opening Sept. 22, architects Mario Bellini from Italy and Rudy Ricciotti from France used the latest in computer technology to create what is the most significant, innovative architectural expansion project to the museum since I.M. Pei shook up the institution with his glass pyramid in 1989.

Described as an iridescent dragonfly wing, flying carpet, wind-blown veil, scarf or sail, or Bedouin tent, the new structure has elicited mostly warm early reactions (unlike the initial outcry against the pyramid). The building is also a much more intimate addition, tucked into the folds of the sprawling monument (822 years old in some parts) and is not clearly visible from the street.

With its new structure and its expanded and restored collection, from which more than 2,500 works will be displayed, the museum says it hopes to "seduce" visitors into learning more about Islamic arts. In the process, the institution has stated a rather more ambitious goal for the $98.5-million-euro project ($123.8 million): to correct common "misconceptions" associated with the Islamic world and "bridge" cultural gaps that can lead to conflict.

The building, which has ground-level and underground exhibit spaces, is covered in a woven, metallic mesh, or "scales" of triangular panels, to protect light-sensitive works. It can be seen through windows around the rest of the museum, as if it were a modern art sculpture itself, complementing the historic surroundings yet appearing capable of flying away at any moment from the palace walls.

"We decided on the solution of a kind of scarf floating within the free space of the courtyard, which we kept open," Bellini said by telephone. "And to have it touch down for a moment at one point, and stay there — as if floating forever."

"Sometimes there is a repulsion effect for the arts of Islam, and for Islam in particular," said Louvre Director Henri Loyrette in a video statement. "Our duty is to explain, to say, to show the luminous side of this civilization and all that it has indubitably brought to the world. And that's what we are simply trying to do with this new department of Islamic art. So the stakes are multiple, but they are questions of understanding that are very, very strong."

And there is no better motivation for understanding one's fellow man than by way of a little French seduction — or the attraction of the beautiful space and its collection, said the Louvre's Islamic art director, Sophie Makariou. "We're not here to give people lessons. We're here to take them by the hand and teach them things and give them pleasure," she said. "I think this kind of visual joy that you feel is the surest motor for teaching.... I believe in an aesthetic slap in the face that you can get, and the magic of the space contributes to that," Makariou said in her office.

The appeal of the building is an element to the Louvre's cultural bridging operation as well. As Bellini put it, the space allows one to plunge into another experience as if on a journey. "Another way would be to hire a tourist agency and travel through the whole Islamic world," he said.

When approached from outside, the roof of the new structure — located within the 19th century Visconti courtyard — immediately rises up as if one were looking up at a sand dune from its base. (Visitors will enter the new galleries without ever having to go outside, and will only be given limited access to the exterior space between the courtyard and new building.) For the outer and inner "skins" of the canopy, architects chose triangular panels of aluminum anodized mesh, with gold on the exterior top layer, silver underneath. The woven mesh softly filters daylight and allows hazy glimpses of the Paris sky and the stone courtyard.

"If you look up, you understand you're in a courtyard," said Bellini, well known for his industrial designs, which have been featured in a retrospective at the Museum of Modern Art in New York, "but on the other hand, you feel you are in a special world, and this magic filter — we can say a flying carpet — it transports your fantasy and your attention elsewhere, while you can still glimpse out and position yourself. That peculiar aspect of being there and not being there is what I think makes our proposal a success."

Adding to the sense of lightness, the undulating mesh, which sandwiches another glass layer, and is supported with steel tubing, rests on only eight slim pillars at different angles, and a rectangular circumference of glass panels forms an almost invisible side barrier looking onto the old stone courtyard.

Creating a modern architectural addition to the world's most visited art museum in a pocket of space was a hefty challenge but a source of inspiration, said the architects. "For an architect, a difficult challenge is the best possible condition to have," Bellini said. "When given a carte blanche, it's horrible; it can easily go wrong. And when you are challenged by a difficult context, you concentrate your mind in a different way ... it makes the outcome much better."

When creating the design, Ricciotti said he was influenced by Montesquieu's 1721 tale of Persians traveling to Paris. "I also wanted natural light, rain, the sky, clouds to accompany the glass that floats," he wrote by email. Ricciotti designed the new Jean Cocteau Museum in the South of France and Marseille's Musée des Civilisations de l'Europe et de la Méditerranée, expected to open next year.

The new wing will unveil never-before-shown precious works from the 7th to the 19th centuries, stretching from Spain to India, including pieces drawn from the Louvre's collection of some 15,000 pieces, plus 3,400 other works on permanent loan from the Musée des Arts Décoratifs.

Adjoining the new wing, a redesigned exhibition space will open at the same time, titled "The Eastern Mediterranean Provinces of the Roman Empire." Previously, Islamic artworks were kept in a relatively small section within the department of Near Eastern antiquities.

Restored, forgotten works such as a 14th century Mamluk porch were reinstalled inside the new galleries , as was a 12-meter-long Ottoman wall of nearly 600 ceramic pieces intricately painted in dazzling blues. Works will be linked to their historical contexts, and multimedia programs are meant to add depth to "overly simplified" ideas about the Islamic world.

"One thing Westerners ... know very little about is the fundamental idea of the level of extreme diversity within the Islamic world," Makariou said. Exhibits will discuss the multiple languages, cultures, religions and art forms — including figurative depictions — in Islamic culture.

The Louvre also will display a 16th century Ottoman drawing of a veiled prophet Muhammad at the opening in September.

A role for the Louvre as a kind of goodwill ambassador for Islam through the arts is a complex and ambitious one in this strictly secular country, with the largest Muslim population in Western Europe and strategic ties to Islamic countries — a few of which have provided much of the funding for the project, including Saudi Prince Waleed bin Talal's Alwaleed Bin Talal Foundation; King Mohammed VI of Morocco; Sheikh Sabah al Ahmed al Jabbar al Sabah, the emir of Kuwait; Kaboos ibn Said, sultan of Oman; and the republic of Azerbaijan).

For one, there is some confusion around the term "Islamic arts." The museum wants the "Art of Islam" wing (as it is literally titled in French) to demonstrate the breadth of "Islamic civilization" and not be confused with a department of art derived from the Islamic faith.But in practice, many don't instinctively make such a clear distinction between the two.

When Saudi Prince Talal donated $20 million to the project, he said: "Relations between Europe and the Islamic world are going through a turbulent period." The new wing "will assist in the understanding of the true meaning of Islam, a religion of humanity, forgiveness and acceptance of other cultures."

However, Makariou quickly points out that the exhibition is not limited to ideas of peaceful coexistence. "It was a terribly conquering civilization.... It was violent," she said, explaining the reason Islamic art covers such a vast geographic area. "Does the Roman Empire only have nice sides to it? No. But it did count in our universal history. The Islamic world is the same," she said.