Estimated to fetch between USD 2,525,361-3,051,478, the "Star of Kashmir" sapphire sold for USD 3,484,142, with a price of USD 175,202 per carat in Geneva this week.
Set with a cushion-shaped sapphire, weighing approximately 19.88 carats, the sapphire is flanked on either side with cushion-shaped diamonds, weighing approximately 3.02 and 2.72 carats.
The graduated diamond line shoulders and engraved sides are mounted in platinum, ring size.
"A natural Kashmir sapphire of this size and purity is extremely rare and thus, the described gemstone with its combination of outstanding characteristics is a very exceptional treasure," Christies said in a statement.
Other highlight of the auction included an exceptional pear-shaped, D colour, Flawless diamond of 101.73 carats that sold for USD 26.7 million (USD 254,400 per carat), becoming the most expensive colourless diamond ever sold at auction.
The sensational gemstone was the centrepiece of the 300-lot Geneva Magnificent Jewels auction, which broke the USD 100 million mark to achieve USD 102.1 million, the highest total ever for a various-owner jewellery auction in Geneva.