An exceptionally rare 19-carat pink diamond fetched $50 million at auction in Geneva on Tuesday, Christie’s auction house said, setting a new per carat record for a stone of its kind.

The Pink Legacy

The Pink Legacy, which once belonged to the Oppenheimer family which for decades ran the De Beers diamond mining company, was snapped up by American luxury brand Harry Winston, part of the Swiss Swatch group. “$2.6 million per carat. That is a world record per carat for a pink diamond," said Francois Curiel, head of Christie’s in Europe. “This stone is for me the Leonardo da Vinci of diamonds," he added. The rectangular-cut diamond has been graded “fancy vivid"—the highest possible grade of colour intensity.

The buyer

Harry Winston made the winning $50 million bid for a pink diamond at an auction by Christie’s, setting a record price for price paid per carat for a gem of that hue. The stone was immediately rechristened the “Winston Pink Legacy" by its buyers.

Former owners

The 18.96-carat stone was the largest fancy vivid pink diamond ever offered at auction by Christie’s, and comes from the collection of the Oppenheimer family, the former owners of De Beers. It sold after five minutes of bidding, meeting the high estimate. The luxury diamond purveyor renamed it the Winston Pink Legacy.

This isn’t the first time Harry Winston has splashed out on such a rare diamond. The luxury jewelry maker, which Swiss watchmaker Swatch Group AG acquired in 2013, paid $27 million for the 101.73-carat colourless Winston Legacy diamond at a Christie’s auction that year.

The Inception

The stone was discovered in a South African mine around a century ago and was probably cut in the 1920 and has not been altered since. He pointed out that the cut is a “classical so-called emerald cut", which stands out from the typical, more rounded, multi-facetted cuts used today. The classic rectangular cut is traditionally used for white stones, but is rare for pink diamonds.

The sellers

Christie’s, which had refused to reveal the name of the seller, said only four vivid pink diamonds or over 10 carats have ever been offered at auction.

One of them, the nearly 15-carat Pink Promise, was sold last November at a Christie’s auction in Hong Kong for $32.5 million. That amounts to $2.176 million per carat.