102.39-Carat Flawless White Diamond Will be Unprecedentedly Offered ‘Without Reserve’ in Hong Kong

Sotheby’s Hong Kong autumn auction is scheduled to be held in early October. After unveiling its highlights for the modern and contemporary art sales, the auction house has just revealed another leading lot this season: a 102.39-carat D-colour flawless oval diamond, which will be offered without reserve in a single-lot auction.

So far, only seven D colour Internally Flawless or Flawless white diamonds over 100 carats (in regular shapes) have been sold at auction and many fetched over HK$100m (about US$12.9m). Now the eighth diamond will be offered without reserve, meaning the winning bid is the highest bid regardless of its amount or the intrinsic value of the diamond itself. Why is Sotheby’s offering such a valuable diamond with this unprecedented approach?

A 102.39-carat D-colour flawless white diamond will be offered without reserve

Before we answer the question, let’s take a look at the diamond and learn more about its rarity. In addition to its enormous size, the diamond has achieved the highest rankings under the 4Cs, standards by which the quality of a diamond is judged. The diamond is D colour (the highest grade for a white diamond); of exceptional clarity (it is completely flawless, both internally and externally), and has excellent polish and symmetry, the most sought-after grading for the oval shape category.

It also belongs to the rare subgroup comprising less than 2% of all gem diamonds, known as Type IIa. Diamonds in this group are the most chemically pure type of diamond and often have exceptional optical transparency.

One can imagine how large the rough diamond has to be in order to make a polished jewel of over 100 carats, and even rarer to find one of such incredible quality in all aspects. The 102.39-carat diamond was cut from a 271-carat rough diamond discovered in the Victor Mine, Ontario, Canada in 2018. Following its discovery, the rough diamond was cut and polished over a year by Diacore, world-leading specialists in sourcing, cutting and polishing extraordinary diamonds, to bring out its best brilliance, fire and scintillation.

The Victor Mine was discovered by De Beers Group in 1987. It opened in July 2008 to become Canada’s first economically viable diamond deposit discovery and recovered 8.1 million carats of diamonds before it closed at the end of 2019.

The diamond was cut from a 271-carat rough diamond

The Victor Mine closed in 2019

So back to the question of why the auction house offers such rare and coveted diamond with no reserve. Patti Wong, Chairman of Sotheby’s Asia, said: ‘It has been a few deeply transformative months for the auction market. We have been at the forefront of change in the Fine Art and watch categories, with new, pioneering auction formats, and this season, we want to extend this approach to our jewellery sales. The conjuncture offers many opportunities to do things differently: demand has shown tremendous resilience during the first part of the year and we feel it is now time to let the market speak. Diamonds of this calibre attract interest well beyond the traditional pool of collectors. This innovative sale seems to us the best way to introduce this exceptional diamond to the world in the current circumstances where travel is restricted and act as a great indicator of the vitality of the demand.’

This present diamond is the second-largest oval diamond of its kind to be offered at auction. The largest one is a 118.28-carat diamond that sold for US$30.8m (HK$238m) at Sotheby’s Hong Kong in 2013, selling for a record of US$260,252 each carat.


The auction record for the most expensive white diamond was set in 2017 when a 163.41-carat De Grisogono emerald cut diamond fetched CHF 33.5m at Christie’s Geneva.

The 102.39-carat diamond will be offered in a stand-alone live auction titled 10239 on 5 October 2020, with bidding opening online from 15 September. The auction will be preceded by a series of previews in Beijing, Shanghai, New York, Taipei and Hong Kong by appointment only.

102.39-Carat D-Colour Flawless White Diamond

Auction house: Sotheby’s Hong Kong
Sale: 10239
Preview dates: 3-5 October 2020
Preview venue: Hong Kong Convention and Exhibition Centre
Auction venue to be announced
Auction dates: 9pm | 5 October 2020 (or immediately following the Modern Art Evening Sale)
Online bidding starts from 15 September 2020