A Romanov sapphire weighing nearly 198 carats on a diamond-covered bracelet sold for more than 4.1 million Swiss francs ($4.9 million) at auction, vastly higher than the expected price range, Sotheby’s said.

The cushion-shaped sapphire attributed to onetime ownership of Russia’s imperial family was billed as a very rare stone, and had been expected to fetch between 850,000 and 1.7 million francs ($1 million and $2 million) at the Geneva auction late Wednesday.

The buyer, a private collector, wasn’t identified.

The 197.80-carat Ceylon sapphire likely came from the Mughal Empire in south Asia, made its way into Russia’s imperial jewels in the 19th century and is one of the most important surviving gemstones from the Russian court.

Dowager Empress Maria Feodorovna, Czar Nicholas II’s mother, wore the sapphire at the Winter Palace Ball of 1903 — “widely regarded as the last great spectacle of Imperial Russia and immortalized in some of the most iconic images of the Romanov court,” the auction house said.

After the Russian Revolution, the sapphire was recorded in inventory before entering the Soviet government’s dispersal sales of imperial treasures, Sotheby’s said.