Mysterious necklace laden with 500 diamonds fetches $4.8m in Geneva auction

A mysterious necklace laden with some 500 diamonds and with possible links to a scandal that contributed to the downfall of Marie Antoinette, sold for $4.8 million at an auction in Geneva on Wednesday.

The 18th century jewel containing around 300 carats of diamonds had been estimated to go under the hammer at the Sotheby's Royal and Noble Jewels sale for $1.8-2.8 million.

But after an energetic bidding, the hammer price ticked in at $4 million, and Sotheby's listed the final price after taxes and commissions at $4.81 million.

Some of the diamonds are believed to stem from a piece at the centre of the "Diamond Necklace Affair" — a scandal in the 1780s that further tarnished the reputation of France's last queen, Marie Antoinette, and boosted support for the coming French Revolution.

The auction house hailed that the necklace, composed of three rows of diamonds finished with a diamond tassel at each end, had emerged "miraculously intact" from a private Asian collection to make its first public appearance in 50 years.

"This spectacular antique jewel is an incredible survivor of history," it said in a statement prior to the sale.

Describing the massive Georgian-era piece as "rare and highly important", Sotheby's said it had likely been created in the decade preceding the French Revolution.

"The jewel has passed from families to families. We can start at the early 20th century when it was part of the collection of the Marquesses of Anglesey," Andres White Correal, chairman of the Sotheby's jewelry department, told AFP when the necklace went on display in London in September.

Members of this aristocratic family are believed to have worn the necklace twice in public: once at the 1937 coronation of King George VI and once at his daughter Queen Elizabeth II's coronation in 1953.

Beyond that, little is known of the necklace, including who designed it and for whom it was commissioned, although the auction house believes that such an impressive antique jewel could only have been created for a royal family.

Sotheby's said it was likely that some of the diamonds featured in the piece came from the famous necklace from the scandal that engulfed Marie Antoinette just a few years before she was guillotined.

That scandal involved a hard-up nobel woman named Jeanne de la Motte who pretended to be a confidante of the queen, and managed to acquire a lavish diamond-studded necklace in her name, against a promise of a later payment.

While the queen was later found to be blameless in the affair, the scandal still deepened the perception of her careless extravagance, adding to the anger that would unleash the revolution.

Sotheby's said the diamonds in the necklace sold Wednesday were likely sourced from "the legendary Golconda mines in India" — considered to produce the purest and most dazzling diamonds.