Rare gems still dazzle

PUBLISHED : Wednesday, 25 April, 2012, 12:00am
UPDATED : Wednesday, 25 April, 2012, 12:00am


Establishing rarity is of utmost importance to owners of fine diamonds and gemstones. Exquisite diamonds and coloured gemstones of extraordinary quality or size will always be in demand. In addition, like most memorabilia, if a famous person wore, bought or even sold it, the value jumps significantly.

That is why when professionals talk about the world's most significant diamonds and gems, they have such precise descriptions, which clearly denote the gems' place in the hierarchy of jewels. Qualifications can include the largest of a certain cut, the largest of a certain colour, the most internally flawless of a certain size, and so on. With these superlatives come bragging rights to being the world's best, with values to match.

Next month, one of the most historic diamonds, the Beau Sancy, will be up for auction. Passed down by the royal families of France, England, Prussia and the House of Orange, the 34.98ct modified pear double rose-cut diamond has witnessed 400 years of European history and will no doubt make headlines when it is sold on May 15 by Sotheby's.

In recent history, some notable diamonds and gems have qualified within the parameters of fame and perfection laid out by auction houses and gem graders. Here are a few with intriguing stories to match.

First up is the Hope Diamond. Many people falsely believe that the 45.52ct diamond is the largest in the world. It is not, nor is it an internally flawless diamond. The largest blue diamond is a 51.84ct blue round brilliant once handled by Harry Winston that is on display at the Smithsonian Museum in Washington DC. The Hope Diamond takes the honours as the largest fancy dark greyish-blue diamond and over the years has attracted stories that it cursed successive owners as it moved from India to France, Britain and the United States.

The Golden Jubilee is the largest faceted diamond in the world, weighing 545.67ct, and was presented to King Bhumibol Adulyadej of Thailand for his golden jubilee in 1997. It is described as a fire rose cushion cut and its story is reminiscent of the ugly duckling.

When the diamond's owner, De Beers, first examined the 755.5ct brown rough diamond, it considered it quite unattractive as brown is undesirable in diamond grading.

Since it had a D-flawless rough waiting to be cut and being promoted for its centenary celebration, the company set master cutter Gabriel Tolkowsky to the task. He developed new tools and cutting methods to use on the diamond and two years later the result surprised everyone. The ugly brown duckling had transformed into a beautiful yellow-brown swan.

Tolkowsky also cut a 273.85ct, D-colour, internally flawless, heart-shaped brilliant diamond that De Beers christened the Centenary to mark the centennial celebration of De Beers Consolidated Mines on May 11, 1988. By the time he finished cutting it in 1991, it became the world's largest colourless, flawless diamond.

The Graff Constellation is the largest D-colour, internally flawless, round brilliant diamond in the world at 102.79ct. It was yielded from the 20th-largest diamond ever discovered, a 478ct stone unearthed in Lesotho, home of the Letseng mine. At the time, it was the world's most expensive rough to be publicly sold. The Graff Constellation is the first round diamond to surpass the coveted 100ct mark at the Gemological Institute of America and the Hoge Raad voor Diamant in Belgium.

'A breathtaking stone, the definition of rarity. Perfect in shape, colour and clarity with unparalleled brilliance. When you look into the Graff Constellation, you see all the stars in the sky,' said Laurence Graff at the annual Graff exhibition of rare gems in 2010.

In the battle for supremacy, nothing is more spectacular than the Lesotho Promise Diamond, a historic find of a 603ct rough diamond. Graff's team transformed this stone into a one-of-a-kind, dazzling necklace made from 26 D-colour, flawless diamonds, ranging from 55 points to 75ct for a total of 223.35cts. Discovered at the Letseng mine, the Lesotho Promise is the 15th-largest diamond ever discovered.

Graff Diamonds transformed the polished stones into a single piece of jewellery, said to be the most valuable and famous necklace in the world.

No story on important diamonds would be complete without remembering that who wore the diamond can sometimes be more important than the diamond itself.

The Tiffany Yellow Diamond is one of the largest yellow diamonds ever discovered, a cushion shape of 128.54ct. Amazingly, the person who cut it was a mere 23 years old and developed a technique to give it 90 facets - 32 more than a traditional round brilliant - to maximise its brilliance. The diamond lives on as an icon of an era.

Jean Schlumberger famously set the diamond three times, including in its much lauded Bird on a Rock setting, but only two women ever wore it. One was a diplomat's wife, the other a charming actress named Audrey Hepburn, who cemented the diamond's place in history when she wore it in publicity shots for Breakfast at Tiffany's.

In the competition for defining the rarest gem, there doesn't appear to be a clear winner, but rather one winner in each category of carat size, colour, cut and clarity. This list is not exhaustive, of course. The real winner, however, is quite clear. It is the person who wears it. And that, by definition, is a very lucky person indeed.