< Historic Diamonds / Famous Diamonds
The Williamson Pink Star Diamond: The Highest Price Per Carat Ever Paid for a Gem
From a rare Tanzanian rough to a record-breaking $57.7 million auction, the Williamson Pink Star earned its place among the world’s most incredible diamonds.
The Williamson Pink Star Diamond (Courtesy of Sotheby’s)
Natural pink diamonds have always occupied a near-mythical status in the gem world. Truly vibrant pinks remain extremely elusive, especially in sizes over one carat. That is what makes the Williamson Pink Star so extraordinary. Weighing 11.15 carats, graded Fancy Vivid Pink, and boasting Internally Flawless clarity, this diamond sits in a category so narrow it barely exists.
Meet the Expert
- Grant Mobley is the Jewelry & Watch Editor of Only Natural Diamonds.
- He is a GIA Diamonds Graduate.
- He has over 17 years of jewelry industry experience, starting with growing up in his family’s retail jewelry stores.
When the Williamson Pink Star appeared at auction in 2022, it did not simply make headlines. It changed how experts value natural diamonds.
Why the Williamson Pink Star Diamond Is So Rare
According to the Gemological Institute of America (GIA), fewer than 3 percent of all diamonds submitted for grading can be classified as natural colored diamonds. Of those, less than 5 percent appear predominantly pink. Most of these pink diamonds fall into softer ranges of color, such as Faint Pink or Fancy Pink, and very few show the intense saturation required for a Fancy Vivid designation.
Size narrows the field even further. In a study conducted by the GIA examining 1,000 pink diamonds graded between 2008 and 2016, 83 percent weighed under one carat. Against those statistics, a Fancy Vivid Pink diamond exceeding 10 carats is almost unheard of.
The Williamson Pink Star stands as only the second Internally Flawless Fancy Vivid Pink diamond over 10 carats ever offered at auction. The first was the legendary CTF Pink Star diamond, which sold for $71.2 million in 2017, and still holds the world auction record for any jewel.
The GIA described the Williamson Pink Star as “Among the rarest of all gemstones… attaining a Fancy Vivid color grade with pink diamonds in this size requires a very strong inherent bodycolor in the rough crystal… In addition to its exceptional color, the clarity is Internally Flawless – a special combination.”
From Tanzania to the World Stage: The Williamson Pink Star’s Origin
The diamond takes its name from the Williamson Mine in Tanzania, one of the oldest continuously operating diamond mines. The Williamson Mine has earned a reputation for producing pink diamonds with a distinctive, lively hue often described as “bubblegum pink.”
Its most famous historical gem, the Williamson Pink Diamond, weighs 23.6 carats and is set into a brooch by Cartier. Canadian geologist John Williamson, the founder of the mine, presented it to Queen Elizabeth II as a wedding gift in 1947. That jewel remains part of the British Royal Family collection and helped cement the mine’s legacy as one of the few consistent sources of natural pink diamonds.
The Art of Cutting a Fancy Vivid Pink Diamond
Discovering a pink diamond is only part of the battle. Transforming it into a masterpiece demands a rare level of expertise. Master cutters at Diacore, a firm known for handling some of the world’s most important fancy-colored diamonds, accepted the challenge.
Diacore acquired the 32.32-carat rough diamond in 2021 for $13.8 million, fully aware that every decision made during cutting would carry enormous consequences. With fancy-colored diamonds, cutters must balance three competing priorities: preserving weight, maintaining clarity, and intensifying color. Sacrifice too much rough, and the value evaporates. Chase the carat weight too aggressively, and the color saturation suffers.
From rough to polished, the transformation yielded an 11.15-carat cushion-cut diamond with Internally Flawless clarity and exceptional color saturation. Very few cutters in the world possess the skill and confidence to attempt such a feat.
Inside the Record-Breaking Sotheby’s Sale of the Williamson Pink Star
The Williamson Pink Star made its debut at Sotheby’s Hong Kong, offered as a stand-alone auction in the Hong Kong Convention and Exhibition Centre. The room, and those like me watching the livestream, buzzed with anticipation.
Bidding opened at HKD 140 million (approximately $18 million USD) and rose steadily to HKD 165 million (about $21.2 million) and then to HKD 200 million (roughly $25.6 million). At that point, only three bidders remained: one in the room and two on the phone.
The pace slowed as bids climbed in HKD 5 million increments, eventually reaching HKD 300 million, or about $38.5 million USD, prompting applause that suggested a possible conclusion, but bidding continued. When the hammer finally fell at HKD 392 million, approximately $50.3 million USD, the room erupted. Including buyer’s premium, the final price reached approximately $57.7 million USD.
At more than $5 million per carat, the Williamson Pink Star shattered the previous per-carat auction record for any gem, surpassing the $2.65 million-per-carat benchmark set by the Winston Pink Legacy diamond in 2018.
The Williamson Pink Star vs. the CTF Pink Star Diamond
In total value, the Williamson Pink Star now ranks as the second most valuable jewel ever sold at auction, behind only the CTF Pink Star, the 59.60-carat flawless Fancy Vivid Pink diamond that sold for $71.2 million USD in 2017.
It does not compete on size alone. It competes on rarity, clarity, and color saturation at a level the market sees once in a generation. Its sale confirms that the world’s most exceptional natural diamonds command awe and record-breaking prices.
