In Geneva, jewels from the former property of the Russian tsarist family that had been smuggled out of the country during the October Revolution of 1917 were auctioned.
A brooch with sapphires and diamonds and matching earrings changed hands on Wednesday evening for 806,500 francs (765,000 euros).
That was more than double the estimate, as the auction house Sotheby's reported.
The auction house did not disclose who bought the jewels.
The person participated in the auction by phone.
According to Sotheby's, the set once belonged to Tsar Nicholas II's aunt, Grand Duchess Maria Pavlovna.
She had given it to a British diplomat in 1917 who brought it to London.
It was also not announced who offered the piece for auction.
The highest price at the major jewelery auction was achieved by a pair of square diamond earrings, each weighing 25.88 carats, which were auctioned for 5.1 million Swiss francs.
A diamond chain owned by a royal family with a total of 59 carats was auctioned for 4.1 million francs.