LONDON • The jewellery was not seen in public for two centuries.
But last Friday, Marie Antoinette's dazzling diamonds and pearls went on show in London before going on sale next month.
The treasures were secretly whisked out of Paris in 1791 in the aftermath of the French Revolution and have been privately owned by relatives ever since.
The collection, held by the Italian royal House of Bourbon-Parma, is being sold by Sotheby's auction house in Geneva on Nov 14.
The lots include 10 pieces which belonged to Antoinette, last queen of France before the French Revolution.
She was guillotined in Paris at the age of 37 in October 1793.
"The romance, magic and universality of her name is because she represents that sophistication of l'ancien regime. She is it," Sotheby's senior director of jewellery Andres White Correal said.
"It is the sale of the 21st century. Because how do you top Marie Antoinette? Also, because it's so scarce. There isn't much left."
The highlight is Queen Marie Antoinette's Pearl, a natural pearl and diamond pendant valued at US$1 million (S$1.38 million) to US$2 million.
A natural pearl and diamond necklace composed of three rows of more than 100 slightly graduated pearls is expected to fetch US$200,000 to US$300,000, as are a pair of natural pearl and diamond pendant earrings.
A monogrammed ring containing a lock of her hair is valued at US$8,000 to US$10,000.
When King Louis XVI, his wife Antoinette and their children tried to flee the French Revolution in March 1791, the royal jewels were smuggled out of the country into the trust of a confidant in Brussels.
They were then sent on to relatives in Austria and passed down through the generations.