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  • Frank Hall

"The Bleu Royal"


A 17.61 carat Fancy blue diamond was the most valuable gem sold in 2023 by Christie’s Geneva for $43.8 million US.  This pear-shaped diamond is the largest internally flawless fancy vivid stone ever to be sold at auction.  Blue is among the rarest of all coloured diamonds and colour is the most important of the 4 C’s.  It is produced by the random presence of the atomic lattice-bound trace element boron in the stone’s carbon structure when it is formed in the earth’s core.


One of the earliest documented blue diamonds is the “Hope Diamond” (45.52 carats) that was believed to have been discovered in the Kollur mine, India in the seventeenth century.  Blue diamonds are also found in South Africa and Western Australia.


Since the 1950’s, methods have been developed to change a diamond’s appearance, adding colour to a colourless stone or making synthetic stones with natural properties.  These are “enhanced diamonds” and do not have the Natural Blue diamond value nor the investment potential.  Since 2015 when a Hong Kong billionaire bought a 9.75 carat blue diamond, named after his daughter “Zoe”, they have become the most sought-after gem at auction.  The Star of Josephine, found in 2014 at the Cullinan diamond mine in South Africa, weights 12.03 carats and is one of the most flawless ever discovered and estimated at $35 million US.


Courtesy of Canadian Professional Appraisers


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