Editor’s Note
This article details the record-breaking auction of the ‘Williamson Pink Star’ diamond in Hong Kong, which achieved the highest per-carat price ever for a pink gemstone.
In October 2022, the ‘Williamson Pink Star’, an 11.15-carat internally flawless fancy vivid pink diamond, was sold at Sotheby’s Hong Kong for a staggering HK$453,223,000 (including buyer’s premium). This translates to a record-breaking price of approximately HK$40.65 million per carat, making it the most expensive pink diamond ever sold per carat. The winning bidder was a collector from Florida, USA.
Auctioneer Ian McGinley opened the bidding at HK$140 million, sparking a 20-minute bidding war. After 11 bids, the price reached the HK$200 million mark. The contest then narrowed down to a duel between Patti Wong (then Global Chairman, now departed) and a gentleman in the room.
The hammer fell at HK$392 million to the gentleman with paddle number ‘8808’, prompting applause from the audience. Patti Wong and Nathan Drahi (Managing Director, Asia) later went to congratulate the winning bidder.
The Williamson Pink Star’s exceptional price is justified by its top-tier characteristics. It boasts the highest color grade of ‘Fancy Vivid Pink’, an ‘Internally Flawless’ clarity, and is a chemically pure ‘Type IIa’ diamond – a category comprising less than 2% of all diamonds. Its 11.15-carat size makes it the second-largest internally flawless fancy vivid pink diamond ever to appear at auction.
With the closure of Australia’s Argyle mine, the world’s primary source of pink diamonds, prices for top-quality pink diamonds have been steadily rising. Pink diamonds are exceptionally rare, constituting less than 3% of all GIA-graded colored diamonds, with less than 5% of those being primarily pink. Only about 4% of natural pink diamonds achieve the ‘Fancy Vivid’ grade, and most are small. Only two fancy vivid pink diamonds over 10 carats have ever appeared at auction: the ‘CTF Pink Star’ and the ‘Williamson Pink Star’.
The diamond’s name pays homage to two iconic pink diamonds. ‘Williamson’ references the ‘Williamson Pink Diamond’, a 23.60-carat stone gifted by Canadian geologist Dr. John Thorburn Williamson to Queen Elizabeth II as a wedding gift in 1947. It originated from the Williamson Mine in Tanzania. The ‘Pink Star’ part of the name is taken from the record-holding ‘CTF Pink Star’, a 59.60-carat diamond sold for HK$553 million in 2017. Both the Williamson Pink Star and the CTF Pink Star were cut by the renowned diamond manufacturer Diacore.
• Williamson Pink Star (2022): HK$453,223,000 | Record: Highest price per carat for a pink diamond.
• CTF Pink Star (2017): HK$553,037,500 | Record: Highest price ever for any diamond at auction.
• Winston Pink Legacy (2018): CHF 50,375,000 (~HK$390 million) | Previous per-carat record holder.