A Tiffany fancy blue diamond ring sold for $2.4m at Sotheby's Magnificent Jewels sale on April 18, 2012.
The auction, which realised a total of $43.1m with 88% sold by lot, set a record for the highest-ever total for a jewellery spring sale at Sotheby's New York.
"The salesroom yesterday was electric, and exuberant bidding led to another record total for our jewellery sales in New York," commented Lisa Hubbard, chairman of Sotheby's international jewellery division. "This is the real strength of auctions: bringing jewels to the light of day after decades spent in private collections."
The Tiffany piece was a surprise top-lot at the auction, with many estimates far exceeding that of the ring. The item was given a pre-sale estimate of $300,000-500,000, displaying an outstanding 386.9% increase on estimate.
The dazzling 3.54 carat marquise-shaped diamond of fancy blue colour sits on a platinum mounting set with European- and single-cut diamonds. Bearing the all-important "T" for Tiffany signature and complete with fitted box, the ring soared past estimates despite having two diamonds missing.
The sale was followed by a huge cushion-shaped diamond ring in fancy vivid yellow colour. The piece, weighing 23.02 carats, achieved $1.87m against an estimate of $2m.
The sale came just one day after Christie's saw another record set in its Magnificent Jewels sale on April 17. The diamond known as the Clark Pink, from the Huguette M Clark collection, sold for $15.7m, becoming the most valuable pink diamond sold in the US.
The market for coloured diamonds is particularly strong at the moment, with Tiffany reporting a 25% profits increase in the first quarter of 2011. Paul Fraser Collectibles brings you further tips on the jewellery market here.