GREEN WITH ENVY
Coloured diamonds, in particular the rare greenhued stones, are increasingly gaining favour among collectors and investors.
Beautifully crafted in the style of a glittering three- dimensional astrolabe or celestial object d’art, De Beers’ Wondrous Sphere incorporates 476 polished and rough diamonds placed on orbiting white gold rings articulated around a 13.17- carat olive green rough diamond. That centre diamond took De Beers ( www.debeers.com) chief diamond buyer Andrew Coxon nine months to find. Coxon is also the president of the De Beers Institute of Diamonds.
“The design required a rough diamond of stature and beauty,” he explains, adding the diamond would have probably gone straight to the polishing wheel if he hadn’t “rescued” it.
Natural vivid green diamonds are the second-rarest diamonds to be found naturally — fancy red diamonds being the rarest — says Coxon, who has bought and sold some of the world’s most famous and largest diamonds. They include the 59.60- carat CTF Pink that came from a 132.5- carat rough diamond mined by De Beers in 1999 and which was bought by jewellery retailer Chow Tai Fook at Sotheby’s Hong Kong last April, setting a new world auction record for any diamond at US$71.2 million (S$94.9 million) or US$1.19 million a carat. In 2016, Chow Tai Fook set the auction world record for a fancy vivid green diamond when it bought Aurora Green for US$16.8 million or US$3.3 million per carat. At 5.03 carats, Aurora Green was a fraction of the size of CTF Pink yet achieved a much higher per carat price. It was also the largest fancy vivid green diamond sold at auction, attesting to the rarity of the most sought-after
saturated colour among green diamonds. While other coloured diamonds form as a result of a contamination in the carbon crystal (such as boron for blues and nitrogen for yellows), the green results from millions of years of exposure to natural radiation beneath the surface of the earth.
The largest and perhaps finest natural green diamond known is the 40.7- carat Dresden Green, a pear-shaped diamond first acquired by Frederick Augustus II, king of Poland, from a Dutch merchant in 1741. It now resides permanently in the Green Vault of the Dresden Royal Palace. The second largest green diamond, Gruosi, is owned by De Grisogono and weighs 25 carats. It is set in a gold ring with 282 black diamonds.
The majority of naturally irradiated diamonds only maintain their green colouring on the surface (also known as skins) and often lose that rare colour during the cutting process. Among these rare stones very few have a pure fancy green colour, with most green diamonds containing a modifying hue (blueish, greyish or yellowish) that will greatly affect the pricing of the stone. “The most attractive modifier is the blue green. They can have a wonderful Caribbean Sea colour. For me, as a professional, I prefer those to the straight vivid green because it has a warmer hue. But it’s not as rare as the vivid green. The least valuable are the greyish yellowish green diamonds, which are actually very affordable. You could buy a threecarat greyish yellowish green for US$15,000 to US$20,000 per carat,” explains Graeme Thompson,
The green results from millions of years of exposure to natural radiation beneath the surface of the earth.
Bonhams’ director of jewellery in Asia.
He points out: “Yellowish and greyish green diamonds are featured in our auctions quite frequently, but we’ve never had a fancy vivid green diamond. We did have a 1.24-carat fancy intense green diamond in 2015, which sold for HK$1 million.”
Bonhams ( www.bonhams.com) will offer a beautiful fancy deep green diamond in May, which Thomson describes as having “a
Bonhams will offer a beautiful fancy deep green diamond in May.