High jewelry houses are traditionally at the tail end of the diamond supply chain. Once they're extracted, rough stones are typically acquired by specialist diamond cutters and polishers, who analyze each stone -- sometimes for up to a year -- to determine the ideal cut in which to shape them. Only after this process are the polished gems usually presented to high jewelry houses, who set them into glittering creations.
But now a handful of houses are keen to master all stages of a stone's journey from rough to final jewel. In September, for example, British luxury jewelers Graff Diamonds bought the uncut Lesedi La Rona, the world's second largest diamond, for $53 million.
"It's become en vogue for brands to say they've acquired a rough diamond, and organized the stone's cutting and polishing," says Vartkess Knadjian, CEO of the 228-year-old diamond company Backes & Strauss. "That provenance will have tremendous interest for the consumer."
The 1,109-carat Lesedi La Rona first made headlines last June, when its seller, Canada's Lucara Diamond Corp, broke with tradition and offered the uncut stone at a Sotheby's auction (most rough diamond sales are completed privately), with an estimated price set at $70 million. When the stone failed to sell, the company sold it to Graff for almost $20 million less.
Company chairman Laurence Graff said he considers exceptionally large rough diamonds a "phenomenon and the most extraordinary discoveries on our planet." The house has shaped at least 11 roughs in the past decade. In 2006, Graff presented the Lesotho Promise necklace with 26 D-color, flawless diamonds cut from a single 603-carat rough; and in 2016, Graff transformed four rough stones into five diamonds, including the identical, 50.23-carat, emerald-cut Eternal Twins.
"Our clients are excited to see what we will reveal from (rough stones)," Graff added.
As one of few high jewelry houses with its own cutting and polishing capabilities, Graff has an obvious advantage when it comes to processing rough diamonds in house. But a lack of such infrastructure hasn't stopped other firms from trying: 25-year-old Swiss jeweler de Grisogono recently entered a ground-breaking partnership with Dubai diamond trader Nemesis International that essentially gives de Grisogono first dibs on whatever the company mines.
Fawaz Gruosi, founder and creative director of de Grisogono, was behind the company's acquisition of the rights to the 404-carat "4 de Fevereiro," the largest rough white diamond found in Angola, from Nemesis in May 2016. After it was discovered in the Lulo mine in Lunda Sul Province in February 2016, de Grisogono arranged for the stone to be analyzed in Antwerp, Belgium, before being sent to New York, where 10 diamond cutters mapped, plotted, cleaved, laser-cut and polished the gem over 11 months. The de Grisogono team then conceived and executed the final design in Geneva.
The result of this international effort, a 163.41-carat emerald-cut diamond suspended from an exquisite emerald-and-diamond necklace, is currently on a world tour, and will go under the hammer at Christie's Geneva on Nov. 14. It's expected to fetch around $30 million.
"Other surprises are in the pipeline," said Gruosi of the brand's rough diamond agenda. "This is just the beginning."
Buying rough stones directly from reputable dealers and mines can also give jewelers greater peace of mind. When you know the source of your stones, you can seek out the appropriate assurances that they were mined and sold under fair conditions.
This has been a draw for Caroline Scheufele, co-president and artistic director of Chopard, who launched a campaign to bring more eco-friendly practices to jewelry-making in 2013. This passion for sustainability led her to the discovery of a 342-carat, D-color, flawless rough from Botswana's Karowe mine, one of the world's first diamond mines to achieve a Fairmined certification, which denotes responsible mining practices. The rough was christened the Queen of Kalahari and produced 23 diamonds (five of which are over 20 carats), which were set into a suite of six outstanding jewels.
Chopard unveiled the resulting Garden of Kalahari collection at a celebrity-studded bash during Paris Haute Couture Week this past January, and it was later displayed in cities around the world, including Tokyo and Cannes.
"People increasingly want to know the whole supply chain," Scheufele said. "No matter what industry -- whether fashion, architecture or cars."