Blue Diamonds - Fancy Colored Diamonds

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At Hard Carbon Inc. we are thrilled to share some exciting news! In April all eyes will be on Sotheby’s Hong Kong when the DeBeers Cullinan Blue Diamond goes to auction. This fancy colored diamond will be the largest vivid blue diamond ever to go to auction. Unlike other infamous gems this fancy colored diamond is brand new to the market – only being discovered in its raw form in 2021. Found in the Cullinan mine in South Africa it originally weighed a whopping 39 carats. The mining giant De Beers partnered with diamond manufacturer Diacore to purchase this rare blue diamond. In recent months the two companies worked together to have the stone cut and polished and the result is a flawless 15.10 carat blue diamond. The DeBeers Cullinan Blue Diamond is now the largest vivid blue diamond to go to auction. The Gemological Institute of America has given it an exceptional grading of internally flawless; only five blue diamonds have ever gone to auction and none over 15 carats. The auction at Sotheby’s in April will truly be an historic event.

In the world of fancy colored diamonds blue diamonds are among the rarest and most sought after. Blue diamond’s get their hue from the presence of boron within the diamond’s carbon structure. Interestingly, people often confuse blue diamonds with sapphires, but they are completely different gems in structure – sapphires are from the corundum family and have traces of magnesium, copper, chromium, iron and titanium. Unlike other diamonds, experts believe that blue diamonds are actually formed in a lower part of the Earth’s mantle and that the boron that creates their blue hue is from serpentinite which flows down the earth’s mantle from the ocean’s tectonic plates.

Blue diamonds are so rare they count for only 0.1% of the mined fancy colored diamonds. While you will often hear that pink diamonds are the rarest that is due to increased demand rather than reduced supply. The reason for this scarcity is that blue diamonds are only found in three mines in the world: India, Australia and South Africa. The Cullinan mine has not only been home to some of the world’s best known blue diamonds but also yielded the incredible 530-carat Great Star of Africa.

Interestingly, a blue diamond is one of the world’s most famous diamonds – the Hope Diamond. Discovered in the 17th century in India the Hope Diamond has a complicated history with it changing ownership several times and even being stolen and re-cut at one point! The Hope Diamond is a 45.52 blue diamond and after residing with King Louis XIV of France it ended up in 1839 being owned by the Hope banking family (hence its name). In 1949 it was purchased by gem merchant Henry Winston who donated it nine years later to the National Museum of Natural History where it is on permanent exhibition.

Another famous blue diamond is the more recent Zoe Diamond. It went to auction in 2013 and was part of the Mellon collection; it had been owned by collector and philanthropist Rachel Lambert Mellon. This blue fancy diamond had been cut into a teardrop shape and weighs in at 9.75 carats. Mounted on platinum it sold for twice its original estimate for $32.64 million. The successful bidder, based in Hong Kong, named the diamond the ‘Zoe’ after his young daughter.

Fashioning a raw diamond from the state it is found in to what goes to auction takes great planning, skill and care. Interestingly cutting down a blue diamond allows for little to no room for mistakes. Unlike other fancy colored diamonds, because of their formation every facet of a blue diamond is integral to the final valuation of the diamond. Any mistake while cutting a blue diamond could result in loss of the blue hue and drastically reduce the value and beauty of the diamond. Diamonds like the DeBeers Cullinan Diamond can take months for diamond cutters to plan and execute the final design for the diamond. There are only a small group of diamond cutters in the world who can do this work to create such a flawless diamond.

The auction world is buzzing in advance of the April event. Sotheby’s is sending the DeBeers Cullinan Blue Diamond to several of its locations prior to the sale. If you wish to see the diamond in person you may be able to see it in London, Dubai, Singapore, Shanghai, Beijing, Shenzhen, and Taipei before it returns to Sotheby’s Hong Kong for the auction.

At Hard Carbon Inc. we are industry leaders in fancy colored diamonds. We work with investors across North America and around the world to source the best fancy colored diamonds for investment. Due to our large, extensive networks of clients we are often able to sell and purchase diamonds in a timely manner. Whether you are new or experienced in the fancy colored diamond market we encourage you to get in touch with us so we can help guide you on this fascinating investment journey.