The 'Pink Legacy', a diamond weighing just under 19 carats, fetched a record 50.375 million Swiss francs ($50 million) as it outshone all other auction lots at Christie's in Geneva on Tuesday.
Graded "vivid", the highest rating for a pink diamond's color, the gem is internally pure with a rectangular cut, and mounted on a platinum ring.
Once owned by the Oppenheimer Family, who built De Beers into the world's biggest diamond trader, the diamond had a pre-sale estimate of $30 to $50 million. The identity of the seller was not disclosed.
Vivid colored diamonds are the most strongly saturated gems, displaying the optimum hue of the stone. Most pink diamonds of this color weigh less than one carat, the auction house - which was holding its semi-annual jewellery sale - said.
Christie's said the 'Pink Legacy' achieved a new per-carat record for a pink diamond, and was the second most expensive one ever sold at auction.
($1 = 1.0073 Swiss francs)