A rare Islamic crystal jug that was mistaken earlier this year for a cheap French claret pitcher has sold at auction for almost $5.6 million.

The jug was mistaken earlier this year for a French wine pitcher. Christie’s said it has now been identified as “one of the rarest and most desirable works of art from the Islamic world.”

An anonymous bidder bought the 1,000-year-old rock crystal ewer — one of only seven of its kind known to exist — during a sale of Islamic and Indian art at Christie’s auction house in London. The sale price of $5.58 million includes the buyer’s premium.

In January, Lawrences auction house in southwest England identified the object as a 19th-century French claret jug and offered it for sale for $175 to $350. Some collectors sensed it was more special and, after a bidding war, the jug sold for $383,692.43, more than 1,000 times the list price.

The auction house said the original sale had been annulled by agreement between the purchaser and the original owners, who wish to remain anonymous.

The slim-necked vessel, carved from a single piece of rock crystal and decorated with elaborate engravings of cheetahs, was made for the court of the Cairo-based Fatimid dynasty, which ruled a swath of the Middle East and North Africa between 908 and 1187. Many artifacts from the era were lost when the Fatimid treasury was broken up by the Ayyubid rulers who succeeded them in the late 12th century.

Only six similar rock crystal ewers are known to survive, including one in London’s Victoria and Albert Museum and another in the Louvre in Paris.

Another, part of the Pitti Palace collection in Florence, was dropped and smashed by a museum staff member in 1998. Restorers have worked without success to rebuild it.