Spectators in a packed auction room at Sotheby's looked on as bids for the baby-pink and diamond-encrusted Cartier piece surpassed expectations, which had put the final sale price at 750,000 to 1.5 million francs.
The bracelet, described by Sotheby's as the property of "a lady of title", was offered by an unnamed member of the Spanish royal family.
It was the star lot in a huge jewellery sale of nearly 600 items.
Described by Sotheby's as a "unique and highly important" item of jewellery, the bracelet was made in the 1920s and is 186 millimetres (just over seven inches) long.
It resembles an articulated band of vines bursting with conch pearl "fruits".
The band is set with diamonds of various shapes, all of them embellished with black enamel, according to Sotheby's.
The bracelet's original owner, Victoria Eugenie, was born on October 24th 1887, at Balmoral Castle in Scotland.
Her grandmother was Princess Beatrice of the United Kingdom, youngest child of Queen Victoria and Prince Albert.
To her family and the public, she was simply known as Ena.
Although she married King Alfonso of Spain in 1906 and went on to have seven children with him, they separated, whereupon Ena purchased a chateau in Vieille Fontaine, near Lausanne.
She lived there until her death on April 15, 1969, at the age of 81.