11.15ct Williamson Pink Star Expected to Fetch Over $21 Million

One of the world’s purest, most saturated pink diamonds was unveiled on 1st September at Sotheby’s London, ahead of a world tour, taking in Dubai, Singapore, Taipei and Hong Kong, where it will be offered in a standalone, single-lot auction on 5th October.

At 11.15 carats, the Williamson Pink Star is the second largest internally flawless fancy vivid pink diamond to ever appear at auction – outsized only by the record-breaking CTF Pink Star, the 59.60-carat oval mixed-cut diamond, which sold at Sotheby’s for $71.2 million in April 2017, and still holds the world auction record for any diamond, gemstone or jewel.

Such is the perfection and purity of the Williamson Pink Star that, with an estimate of $21 million, it has the potential to set a new per carat price record for a fancy vivid pink diamond. Diacore, who were also responsible for manufacturing the 59.60-carat CTF Pink Star into its final form, also polished the Williamson Pink Star’s rough stone into the final faceted diamond.

Wenhao Yu, Chairman of Jewellery and Watches at Sotheby’s Asia, said: “The discovery of a gem-quality pink diamond of any size is an extremely rare occurrence – something that, with the recent closure of the Argyle mine, seemed until recently – highly improbable. Driven by a limited supply and rising demand, prices for top-quality large pink diamonds over 5 carats have increased exponentially over the past decade, serendipitously setting the scene for the appearance now of this one-of-a-kind stone.”

A natural wonder of nature, the extraordinary cushion-shaped stone has been named in homage to two legendary pink diamonds: first, the CTF Pink Star, noted above; and second; the celebrated ‘Williamson’ stone – a brilliant-cut diamond of 23.60-carats given as a wedding present to Her Majesty Queen Elizabeth II in 1947 by the Canadian geologist and royalist, Dr. John Thorburn Williamson, who owned the Williamson mine in Mwadui, Tanzania, where it was discovered.

Curiously, what gives pink diamonds their coveted colour remains a mystery. Whereas other diamonds take their hue from specific trace elements, such as nitrogen for yellow diamonds, or boron for blue diamonds – the cause of the pink hue is still not fully understood. It is thought that the colour is caused by a distress in the atomic level, during the stone’s formation process deep within in the earth.

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