The spectacular diamond, set in a simple ring, sold to an Asian private buyer who bid for the rare gem over the telephone. A Sotheby's spokesperson said they were not yet able to reveal the buyer's identity.
"It is difficult to imagine a diamond that better illustrates the term vivid pink than this outstanding stone...the color is simply astonishing," David Bennett, worldwide chairman of Sotheby's International Jewellery, said in a statement announcing the sale.
The most expensive pink diamond ever to sell at auction remains the 24.78 carat 'Graff Pink,' which sold for $46.2 million at Sotheby's in November 2010.
However, yesterday's 'Unique Pink' sale eclipsed the previous record for a fancy vivid pink diamond, set by the 'Sweet Josephine' at a Christie's auction in November 2015.
That 16.08 carat diamond sold for $28.5 million to Hong Kong billionaire, Joseph Lau, who purchased it for his then 7-year-old daughter, Josephine.
As colorful as these diamonds may be, they pale in comparison to the diamond Lau purchased for his daughter at a Sotheby's auction the very next day.
That 12.03 carat blue sparkler, dubbed the "Blue Moon of Josephine
", sold for an eye-watering $48.4 million, making it the world's most expensive diamond ever.
But that record may soon be challenged, with the 14.62 carat 'Oppenheimer Blue' -- the world's largest vivid blue diamond ever to be sold at auction -- going under the hammer at a Christie's auction in Geneva on Wednesday night.