100 Carat Diamond Club

A section of the “A Heritage in Bloom” necklace by Wallace Chan for Chow Tai Fook showcases the 104-carat Cullinan Heritage diamond. For a complete photo gallery of diamonds in the 100-Carat Club Registry, see Rapaport Magazine, October 2015 print edition.

In the world of rough diamond mining, any diamond weighing more than 10.8 carats is designated as “special” and offered to wholesale buyers separately from the run-of-mine production. Of the tens of millions of carats of diamonds that have ever been mined, the number of polished diamonds weighing 100 carats or more is thought to be fewer than 100 gems. What then to call these special gems that weigh in at 100 carats-plus? Going beyond the generic 4Cs that describe diamonds, they represent a “fifth” C — colossal.    The size of a diamond is impacted by both nature and man. Because of diamond’s chemistry, only the purest large diamonds survive the mining and recovery process. Diamonds with significant inclusions usually break apart somewhere along the way. Wars, divorces and other upheavals all take their toll. Stones are traded, hidden, lost and found, sometimes shedding a few carats along the way.    Throughout the recorded history of polished diamonds, stones have been documented with varying degrees of certainty. The Rapaport 100-Carat Diamond Club Registry lists the verified information available to date for the members of the exclusive 100-carat diamond club. Oldies but Goodies    Dating back to 1304, the 105.60-carat Koh-i-Noor diamond, mined in the Golconda region of India, the famed source of some of the world’s most highly valued diamonds, is the oldest of the historic stones. The aptly named Mountain of Light had a turbulent journey through Mughal history until it was claimed by the British East India Company. Now owned by the British royal family, it is part of Queen Elizabeth’s Crown and on display with the Crown Jewels in the Tower of London.    In 1701, Golconda region mines produced a 410-carat rough, which yielded the 140.50-carat cushion-cut Regent diamond, now in the Louvre Museum in Paris. As the Indian mines were coming to the end of their production, diamonds were discovered in the Minas Gerais region of Brazil in 1725. This mining area produced the Star of the South, a 128.48-carat cushion-cut fancy light pinkish-brown diamond.    Brazil’s reign as the prime source of diamonds lasted only until 1867, when diamonds were discovered in South Africa. In 1877, the Kimberley mine produced a dazzling 287.42-carat yellow rough from which the 128.54-carat cushion-cut fancy yellow Tiffany Diamond was taken, ushering in the modern age of colossal diamonds. Discoveries in South Africa    Nearly all the 100-carat-plus diamonds found in the twentieth and twenty-first centuries come from southern Africa. Unlike run-of-the-mine production, which is sorted and mixed until its origins are lost, the heritage of colossal diamonds is carefully tracked from the moment the larger-than-large rough emerges from the surrounding kimberlite.    The most enormous of the dazzling white diamonds discovered in South Africa was — and still is — the Great Star of Africa, also known as Cullinan I. This 530.20-carat pear-shape white diamond was taken from a rough weighing 3,106.75 carats. It was discovered in 1905 at the Premier Mine in South Africa, which began production in 1902 and was renamed the Cullinan Diamond Mine in 2003 after Thomas Cullinan, its first foreman and chairman.    In 1934, the neighboring Elandsfontein mine yielded a 726-carat rough that was cut into 13 gems, including the 125.65-carat emerald-cut Jonker diamond. Reminiscing about cutting this enormous diamond decades later, the then 90-year-old Lazare Kaplan said, “I needed to create larger tools just to handle the rough.” Modern Finds    More recent colossal diamonds found at the Cullinan mine include a yellow brown 755.50-carat rough that was mined in 1986 and cut into the 545.65-carat Golden Jubilee in 1990 and the 273.85-carat modified heart shape brilliant-cut Centenary Diamond, mined in 1986, but only unveiled by De Beers in its cut form in 1991. In 2009, Cullinan produced a 507.55-carat rough known as the Cullinan Heritage. The rough was studied for three years before cutters working for the buyer, Hong Kong–based Chow Tai Fook, decided to take a round diamond from it. The 104-carat DIF stone was unveiled in November 2014 and named the Cullinan Heritage.    While the Cullinan mine is a consistent source of very large diamonds, the most prolific producer of colossal diamonds has been the Letšeng mine of Lesotho, the mountain kingdom that is an enclave of South Africa. It is unique among diamond mines in that it has a relatively small production in overall caratage, but a significant production of enormous rough.    While the mine routinely produces rough weighing more than 100 carats, its most headline-grabbing finds go well beyond that size. These include the 603-carat Lesotho Promise, found in 2006, the 493-carat Letšeng Legacy, found in 2007, the 478-carat Light of Letšeng mined in 2008 and a 550-carat white diamond called the Letšeng Star discovered in 2011. Each of these yielded a 100-carat-plus polished diamond of the highest color and clarity. The 132.55-carat Golden Empress, unveiled by Graff Diamonds in 2015, was taken from a newly mined 299-carat yellow rough.    A glance at The Rapaport 100-Carat Diamond Club Registry shows that fully one-third of the 100 carat-plus diamonds are fancy yellow of some intensity and virtually all are from South Africa. Given that white diamonds usually outnumber yellows, why should so many of the colossals have this hue?    The answer may lie in the presence of nitrogen in the southern Africa kimberlite. Very few yellow diamonds were mined before the discovery of diamonds in South Africa. According to Emmanuel Fritsch, former manager of research with the Gemological Institute of America (GIA), “Most yellow colorations are related to nitrogen. Even for a low concentration of nitrogen, the coloring power of this defect is strong and the resulting color is saturated.” Beauty Unleashed    Every piece of enormous rough presents myriad challenges to the cutter because even in the most transparent stone, much of the stone’s internal structure is hidden from view. It is common for cutters to study a large rough for months, even years, before deciding on how to extract the gem or gems within.    The Cullinan Heritage is a standout for its round brilliant cut as well as its size, clarity and color. There are just three round brilliant-cut diamonds on the 100-carat-plus registry. According to Martin Georgiadis, head of the New York City office of Diacore, formerly Steinmetz Diamond Group, “It’s difficult to get a round 100-carat stone because you are limited to the angles of a well-cut stone, the depth of a nice stone. With a fancy shape diamond, you have more leeway in the facets, you can play with the angles. A pear shape can be longer or wider; a cushion has room for different arrangements of facets.”    Economically, it’s better to take the largest stone possible from the rough but not at the expense of color or clarity. “If there is a 100-plus, go for it,” says Hoda Esphahani, former president and chief executive officer (CEO) of Safdico and now a private dealer. “There is a 20 percent price difference if it is under or over 100. A beautiful emerald cut is going to be more of a premium,” she says, adding, “Beauty really counts.” Even with modern scanning machines in use at the tenders to assist buyers in making their bids, Esphahani notes that inclusions may deny a buyer the 100-carat stone. “There is still a risk,” she says. “No machine can tell you that there is no internal graining. Part of the rough can have graining, part can be clean. You don’t have IF, you have VVS, that’s 30 percent less value.” So too is the difference between a D and an E. Glancing at The Rapaport 100-Carat Diamond Club Registry proves the point: There is not an E among the stones on the list.    Laurence Graff, owner of Graff Diamonds, points out, “A large rough stone can be likened to an extremely valuable jigsaw puzzle. The possibilities are often varied as to what a stone can yield. The diamonds inside the rough may sit very closely together, which creates a cutting risk in itself. Indeed, sometimes we forgo the 100-plus stone for a better-grade stone.”    These distinctions are not certainties when the cutting process begins. “With clarity, sometimes it’s obvious,” Georgiadis explains, “but even if the stone looks clean, until you open it up, you don’t know. Even then, you might be down to finishing the process, and you may see a tiny inclusion, a VVS will pop up.” If it’s near the surface, Georgiadis says, you can polish it away.    “You are never 100 percent sure you will get a D but, based on your experience, you think that it has a good shot to be a D,” Georgiadis continues. If, however, as the cutter makes his way into the stone, it suddenly looks as if a 100-carat stone will more likely be an E, a new plan will be devised. Either the rough will become two smaller stones or the weight of the one large stone will fall below the 100 mark. The tradeoff between color and clarity always tips toward color because a D is so much more valuable than an E.    In the case of fancy yellow diamonds, according to a renowned cutter who asked not to be named, “You want to go with a shape that collects more color. You are continually moving it: 95 vivid is worth more money than a 100 intense, so you go for the vivid. But losing 5 carats of intense is a gamble, too. How confident are you about getting the 95-carat vivid?” The elusive nature of color in diamonds is strongly influenced by the placement of the facets on pavilion and crown. The cutter wants to maintain the intensity of the hue without trapping all the light inside. The light gives the diamond its fire and life.    Graff, who has put his master cutters to work on both white and colored diamonds, says, “The highly crafted principals of symmetry and the polishing of a colored rough are unique, with an entirely different set of skills and tools applied for polishing colored diamonds than white. We study the colored rough carefully to determine the precise angles of the cut that will draw color into the center of the stone. The craftsmen use their artistic flair to intensify the natural fire, brilliance and distinct personality of each stone.” Making the Grade    John King, chief quality officer at the GIA, describes the grading of 100-carat diamonds as the same process used for a 1-carat diamond. But, he says, “The job becomes understanding the relationship of scale. In an average-size diamond, an inclusion may be taking up a relatively small area of the diamond. It may be more visible in a 100-carat stone.” Assessing the impact of the inclusions depends on the experience of the graders. “You don’t want to overreact to the inclusions,” King says. He describes the process of working from the surface through the table plane. “On a 1-carat stone that distance is not great. In a 100-carat stone, you are covering a lot of real estate.”    In grading these huge and valuable gems, GIA strives to complete the process within 24 hours, ideally taking a stone in first thing in the morning and returning it by the end of the same day. The enormous value of these stones makes it imperative to get them out as fast as possible. During that accelerated process, King says, “There could be 20 to 30 people looking at a stone. Just for clarity, you could have four to six people.” Virtually all such stones are graded in GIA’s New York laboratory. The Auction Scene    The modern history of selling colossal diamonds at auction may be traced to a phone call taken by David Bennett, today Sotheby’s worldwide chairman, jewelry, from a dealer in the summer of 1990. Bennett, then director, European jewelry sales, was asked by the caller, “Would you be interested in selling a 100-carat diamond?” The stone was a 101.84-carat modified pear shape, DIF diamond. “No one had ever tried to sell a 100-carat diamond at auction before; there was no precedent for it,” Bennett recalls. “I had only arrived in Geneva from London eight months before. It was a huge gamble.” The timing was not auspicious. This was the summer that Saddam Hussein invaded Kuwait, leading to an economic upheaval. But by then, Bennett was committed to the sale.    That newly mined stone was bought by Robert Mouawad and named the Mouawad Splendor, fetching $12.7 million, or $125,295 per carat at Sotheby’s November 1990 Geneva auction. There was an underbidder from the Middle East who came by after the sale and asked Bennett, “Tell me any other way I can put $12 million in my pocket and walk away.” Bennett relates, “It was a new idea. It started off a stream of them. I became the 100-carat man.”    François Curiel, chairman of Christie’s Asia Pacific, says, “The arrival of 100-caraters has brought the jewelry auctions to a new level. From $15 million to $20 million total sales in the late 1970s, we are now seeing $100 million-plus auction sales.” By keeping a close eye on the global market, Curiel says, “Every 100-carat gem that was offered for sale sold successfully.”    Graff has been a key player in the growth of these sales, amassing the largest collection of 100-carat-plus diamonds on record. By naming and publicizing his purchases, Graff has brought public awareness to these unique gems. The cutting process, he says, depends on people, not technology. “Machines are important, but ultimately it’s about the senses, heart, passion and risk,” says Graff. “There isn’t any machine that can employ those feelings and this is what you need to be able to push a stone to its absolute finest. I remember when we cut the Perfection, the best technology in the world told us we would yield around 80 carats, but I knew with the skill of our master cutter, the late Nino Bianco, we could reach 100 carats. He worked the stone for over a year and created a wonderful diamond of exactly 100 carats.” The Future Rocks    Owned by Gem Diamonds since 2006, the Letšeng mine is expected to produce very large, extremely white diamonds for the next 30 years. But the newest entry in the 100-carat club is Lucara Diamond Corp.’s Karowe mine in Botswana. In operation just over three years, the mine produces what its Chief Executive Officer (CEO) William Lamb calls, “an exorbitant proportion of large stones, more than Letšeng, as good as Letšeng, very white.”    Lamb describes the recovery of a 239.2-carat diamond that nearly turned into diamond dust. “It measured 45 mm by 30 mm by 25 mm. It was blind luck that it made it through the screen.”Even larger stones have emerged in 2015. At Lucara’s exceptional stone tender held in Gaborone in July 2015, a 341.90-carat rough sold for $20.6 million, while a 269.70-carat stone sold for $16.5 million. In August, Lucara recovered a 336-carat, type IIa diamond from the Karowe Mine, suggesting these enormous finds are not anomalies.    Three mining firms, Petra Diamonds, Gem Diamonds and Lucara, have upgraded their recovery plants to protect these enormous diamonds. Petra, which bought the Cullinan mine from De Beers in 2008, expects to continue to recover these stones indefinitely. According to Petra spokesperson Cornelia Grant, Cullinan’s ore body will keep producing large diamonds. “A kimberlite pipe originates from 140 km — 86 miles — below surface,” she explains, “so in geological terms, we are just slicing off a tiny fraction of these geological structures. Cullinan has produced just over 130 stones weighing more than 200 carats and a quarter of all diamonds weighing more than 400 carats.”    Is it possible that the market will be overwhelmed by supersized stones? According to Curiel, “Timing is, of course, very important and we are inclined to offer a 100-carat gem for sale when the market is buoyant. I do not believe that there is a risk of flooding the market because there are many more new potential customers now, particularly from Russia and China, who are very keen to own trophy stones.” The risk, he says, is in finding enough talented cutters. “The world of diamond cutters is very small. If the stone is a beautifully fashioned 100-carat gem, we will always find a buyer.”