The star lot at Sotheby's Geneva show was bought after a fierce bidding war. It had been valued at about $2m.
It was part of a major collection of jewellery sold by Italy's royal Bourbon-Parma house.
Some of the jewels had not been seen in public for 200 years.
The previous record for the most expensive pearl jewel was a necklace once owned by the late Dame Elizabeth Taylor. It was sold for $11.8m at Christie's auction house in 2011.
Sotheby's called Wednesday's auction in Geneva "one of the most important royal jewellery collections ever to appear on the market".
Deputy Chair Daniela Mascetti said: "This extraordinary group of jewels offers a captivating insight into the lives of its owners going back hundreds of years."
But she noted the "inherent beauty of the pieces themselves; the precious gems they are adorned with and the exceptional craftsmanship they display are stunning in their own right".
There were also pieces from King Charles X, the Archdukes of Austria and the Dukes of Parma, including a diamond tiara.
The whole collection was sold for more than £53m.
Marie Antoinette was an Austrian princess before her marriage to France's King Louis XVI. Her extravagant lifestyle turned her into a hate figure in the years leading up to the French Revolution, when many French people could barely afford to feed their families.
She smuggled out her jewellery to her family in Austria before her failed attempt to flee France with Louis XVI and their children. She was guillotined in 1793 at the age of 37.
According to BBC