In the Cut

A 603-carat diamond goes to pieces.


Laurence Graff, the British billionaire jeweler known as the king of diamonds, wanted to own the rock, all 603 carats of it, the moment he hung up the phone last August. The conversation was brief: The Lesotho Promise, the 15th-largest rough diamond on record, had just been excavated at the Letseng Diamond Mine in Lesotho, a tiny, mountainous kingdom landlocked within central eastern South Africa. For a man of Graff’s temperament and ambitions (“I’ve never said no to a diamond,” he says with typical swagger), the opportunity to own a gem of such proportions was utterly tantalizing. Fascinating in its original mined state, the staggering stone could prove a massive windfall for the jeweler, via its potential offspring—many smaller “satellite” diamonds.

Over the years, Graff has owned many extraordinary rocks, perhaps more than any other jeweler in business today. Just last November he scooped up the 493-carat

Letseng Legacy, which hailed from the same pit as the Promise, once again proving his insatiable lust for massive stones. Other notable Graff diamonds include the 100-carat Star of America, the 137-carat Paragon, the 132-carat Sarah and many 50-plus-carat diamonds.

Still, a rough diamond larger than the Promise hadn’t surfaced since the discovery of the 777-carat Millennium Star in the Democratic Republic of Congo in 1993. In addition, the Promise was a beautiful white D-grade color, the most valuable on the calibrating system. And, quite simply, Graff had never owned a rock that big.

While small diamonds, the kind that dapple watches or engagement rings, are hardly scarce, the discovery of a 200-carat-plus rough diamond typically generates headlines. The past couple of years have yielded several large stones—many of them from Letseng. In addition to the Promise and the Legacy, a 215-carat rough diamond mined there last March was sold to Omega Diamonds for $8.3 million. Of course, all of those would be dwarfed by the Cullinan. The largest diamond on record, the Cullinan was unearthed in South Africa in 1905 and weighed in at a monstrous 3,106 carats. But experts are skeptical whether equally impressive diamonds will continue to emerge. As Graff USA president and CEO Henri Barguirdjian puts it, “Finding another stone like the Lesotho Promise is the equivalent of finding a van Gogh that has been lost for a century.”

Barguirdjian would get no argument from the mine worker who first set eyes on the Promise. “She was alone in the sorting room, and she started screaming,” relates Clifford Elphick, chief executive of Gem Diamonds Ltd., which operates the Letseng mine with the government of Lesotho. “People came running. They thought she’d been electrocuted.”

A state-of-the-art diamond scan

De Beers operated Letseng, which excavates an average of 250 carats per day, until 1982, when it was shuttered after the U.S. recession triggered a downturn in the diamond market. Since Gem Diamonds took ownership in 2006, the mine has experienced a major hot streak, cornering the market on enormous stones.

One of the more recent rocks, the Promise, was dispatched to Belgium and put on the block in October 2006 at the Antwerp Diamond Center, a high-security compound overlooking train tracks, where huddled groups of men trade in a members-only, cathedral-ceilinged hall.

While 45 percent of the world’s diamonds are sold by De Beers directly to 93 sight holders (select companies authorized to purchase rough diamonds from the Diamond Trading Company, the distribution arm of De Beers), big stones originating outside the De Beers cartel are often offered at silent auction, typically an advantageous arrangement for the mines. This is because a silent auction can prove tricky for the bidder, who, absent the back-and-forth that takes place in a live auction, submits a single offer—albeit one based on extensive due diligence and knowledge of the market. With the spoils so dazzling, the impulse to bid high is huge. Graff’s bid of $12.4 million for the Lesotho Promise beat out 13 rivals.

“Anything good you don’t buy cheap,” says Graff, shrugging off criticism that he overpaid for the Promise. “We knew the yield would be great.”

But cutting a diamond as complex as the Promise is hardly a snap. One false move on the cutter’s wheel can cause the diamond to explode into a mountain of worthless dust. “We have no insurance,” Graff said prior to cutting, which took place in a diamond-cutting facility in Antwerp. “It’s dangerous.”

The process is much like doing a jigsaw puzzle in reverse. First, experts map the diamond’s many inclusions—or flaws—with the help of sophisticated CT scan–like equipment. Algorithms are calculated to maneuver around those imperfections with a view to producing the most perfect stones. (At Graff’s Antwerp analysis and finishing facility, more than four months were dedicated to this process for the Promise.) Finally a computer-driven laser breaks the diamond apart.

By comparison, when Joseph Asscher, the greatest diamond cutter of the early 20th century, cleaved the Cullinan diamond, he had only his eye, a hammer and a chisel at his disposal. According to legend, Asscher fainted from the pressure after he split the Cullinan in two.

But while the early stages of modern-day diamond cutting are incredibly high tech, the bulk of the polishing is resolutely antediluvian. In Graff’s Belgian headquarters, for example, a dozen men cluster in a small, vaultlike basement room, tirelessly rubbing the stones against spinning metal discs sprinkled with diamond powder. Because a diamond is the hardest natural substance, only diamond can cut diamond.

Hours are devoted to perfecting a single facet. Cutters clamp each stone into a vise and lower it onto the wheel, periodically lifting it to examine the progress. Patience is paramount: One facet may require 10 minutes to complete; another on the same diamond can take 10 days. All the while, the specter of the stone exploding hangs above the cutters like the sword of Damocles.

“The last 10 years have brought a tremendous leap in technology, especially where scanning is concerned,” says Graff. “But it’s ultimately the human hand, the artisan, who makes the diamond. Things can go very wrong.” So much so that one of the industry’s unwritten laws is never to brag about a stone to the world at large until it’s finished.

Fortunately for Graff, things went very, very well with the cutting and polishing of the Promise, which took an additional nine months postanalysis. (Midprocess, the rough bits were stored in an on-site safe.) Once his crack team—all 35 members—completed their individual tasks, the yield was 26 D-flawless diamonds weighing in at a total of 224 carats. (As precise as the technicians were, much was lost in the cutting process—a standard occurrence.)

“To reach that kind of yield and produce such a large quantity of flawless diamonds obviously attests to the skills and planning…that took place,” says John King, technical director of the Gemological Institute of America (GIA), which graded the individual stones. “So it’s not only the combination of the inherent material and the rarity of finding that, but also the skill to make it happen.”

According to King, prior to the grading, the GIA did not know that the 26 stones descended from one celebrated source. “Diamonds come to us in anonymity,” he says. “It’s all random. So it’s pretty interesting to see this situation happen.”

Graff is, of course, over the moon at the outcome. “The end of this journey is a historic moment,” he says. “Never before have 26 D-flawless stones come out of a single piece of rough.”

Now, all that’s left is to find new homes for the sparklers. Ideally, the lot, which includes a 43-carat heart-shaped stone and a 27-carat round brilliant-cut diamond, will be sold lock, stock and rock to a single buyer.

Given the estimated total price tag of $50 million, however, that may be a bit of magical thinking on Graff’s part. “Whether I make 26 women extremely happy or one remains to be seen,” he says. “But I wish I didn’t have to sell any of them. They are almost too beautiful to see go.”

Photos courtesy of Graff.