The British government has put a temporary export ban on J. M. W. Turner’s Modern Rome – Campo Vaccino, the dreamily beautiful masterpiece that was the artist’s last painting of Rome.

It sold at auction in July for $45 million, but even then the Getty knew they weren’t likely to get their hands on it anytime soon because UK law delays export of significant artistic and historical pieces that have been in the country for at least 50 years to give local institutions a chance to raise the sale price. If a British museum can raise the money, the Getty will be forced to accept payment and the Turner will remain in the country.

Culture Minister Ed Vaizey announced the decision on Wednesday, and gave individuals and organizations until February 2, 2011 to demonstrate serious intent to keep the masterpiece in the country by meeting its market value.

If it appears to be a real possibility that the funds can be raised, the deadline will be extended to August 2 next year, he said in a statement.

When the painting sold this summer, the buzz was that the in-country museums like the Tate Gallery and British Museum weren’t likely to seek out such a huge sum for a Turner since they already have a notable collection and that kind of money is hard to come by these days. The Getty Trust, on the other hand, was very excited to have snagged this piece because it would make Los Angeles the city in the US with the third most Turners after New Haven and Washington, D.C.

The ruling follows the recommendation of the Reviewing Committee on the Export of Works of Art and Objects of Cultural Interest, administered by the Museums, Libraries and Archives Council (MLA), which assesses each object individually to determine whether it’s in the country’s cultural interest to allow a piece to be sold abroad. Lord Inglewood, chairman of the Reviewing Committee, pointed out that even though the UK has the great number of Turner’s paintings, Campo Vaccino is a particularly stellar example of his oeuvre. It’s in outstanding condition (it has only had 2 owners since it was painted in 1839 and both of them treated it with kid gloves) and, as the good Lord puts it, “in a single painting it sums up Northern Europe’s centuries old attitude towards the Mediterranean and the Classical World and its seduction by them.”

The Getty has no choice but to wait it out, and they’re being very pleasant about it. They have tasted the bitter gall of an export ban before. In 2004, the British Museum bought Raphael’s Madonna of the Pinks out from under them thanks to an export ban and feverish fund raising. There was a lot more cash in budgets back then, though. The Getty has reason for optimism.

The monumental stained glass windows created by Marc Chagall for the Art Institute of Chicago were returned to public view today after 5 years. They were removed from their spot in the Marc Chagall Gallery overlooking McKinlock Court in May 2005 to keep them safe from the vibration and dirt during the construction of the new Renzo Piano-designed Modern Wing which opened last year.

While they were in storage, the museum’s conservation team took advantage of the opportunity to deep clean the 36 panels. After nearly 30 years, the windows had developed a white film from atmospheric pollutants that muted their deep color. It was like looking at the street through a dirty windshield. So the conservators whipped out their Q-tips, baby shampoo and water and revealed the original brilliance of the windows.

Marc Chagall (French; b. Byelorussia, present-day Belarus, 1887-1985) first conceived of the idea for the America Windows in 1974 when he visited Chicago for the unveiling of his mosaic in the First National Bank Plaza. At that time, Chagall learned that a gallery in his honor was being planned as part of the Art Institute’s 1970′s expansion program and offered to create the windows for the gallery. After working on the windows’ design, Chagall announced that the theme for the windows would be the American Bicentennial, and, when he learned of Mayor Richard J. Daley’s death in 1976, he decided that the windows would also serve as a memorial to the late mayor.

Chagall designed the America Windows expressly for the Art Institute and created them in collaboration with the French stained-glass artist Charles Marq. Marq fabricated 36 colored glass panels to Chagall’s specifications, and Chagall himself painted his design onto the glass using metallic oxide paints that were permanently fused to the glass through a subsequent heating process. The windows, measuring more than eight feet in height and more than 30 feet in width, are each made up of three parts, each with 12 separate sections. The images on the panels are unmistakably from the hand of Chagall, who infused his landscape of familiar American icons, references to Chicago, and symbols of the fine arts with an ethereality that suggests the creative expansiveness made possible by American freedom and liberty.

The America Windows have been a huge draw ever since. An estimated 38 million viewers enjoyed the windows between their 1977 dedication and 2005 removal. Museum staff were peppered with requests for them during the long 5 years of their absence. Also, Ferris and Sloane kissed in front of them during the art museum sequence in Ferris Bueller’s Day Off, so you know fan pilgrimages have been involved.

Now that they’re back, they’ve been placed in a new location — the east end of the Arthur Rubloff building — and reframed according to Chagall’s original plan, which apparently focuses the light in a special way.

Edit: Here’s a breathtaking video by artist and blogger Shellie Lewis of the refreshed Chagall America Windows looking like they might explode from their own beauty: