De Beers’ undertaking highlights the dilemma faced by diamond miners, who are forecasting diminishing supplies if they don’t discover new caches of gems. Only a blockbuster discovery will enable them to keep long-term production at current levels, according to De Beers and analysts. ... The problem: Only a fraction of the world’s underground diamond deposits are large enough to justify the expense of harvesting them. ... Global diamond production is expected to peak in 2017, when 164 million carats of diamonds are forecast to be produced, according to McKinsey & Co. After that, production is expected to go into a long-term decline, unless major new discoveries are made, McKinsey’s forecasts show. ... De Beers is marshaling new technology, including advanced computer algorithms that can comb through the mass of data the company gathers as it scans the Kalahari for signs of a diamond-studded kimberlite, a pipe of solidified lava containing rich veins of diamonds pushed up from the earth’s mantle. Only about 15 in 100 kimberlite pipes contains even one diamond, and only a fraction of those have enough to make them worth building a mine to harvest the diamonds

Twenty-five years after the first diamonds were found in Canada’s Northwest Territories, it’s still a game of hurry-up-and-wait. For every thousand grassroots exploration projects, only one becomes a mine. Snap Lake, one of three operating mines in the region, was shuttered by De Beers last year, a casualty of harsh geography and falling diamond prices. Government attempts to add production value with a cutting industry collapsed years ago; all that remains of “Diamond Row” in the territorial capital Yellowknife is a line of derelict buildings behind barbed wire. ... And yet the dream lives on. At a time when global miners are shedding assets, De Beers is about to open the largest new diamond mine in the world, Gahcho Kué, 280 kilometers (175 miles) northeast of Yellowknife. A little further north, Rio Tinto Group last year found—and just sold—the largest gem-quality diamond ever recorded in North America at its Diavik mine, the 187-carat Foxfire. Dominion Diamond Corp. last week agreed to extend the life of the neighboring Ekati mine beyond 2020.

De Beers, the world’s biggest diamond company, marked the opening of its Gahcho Kué mine in September. ... the aim of extracting more than 12,000 carats (2.4kg) of diamonds each day. Gahcho Kué is an astonishing endeavour, the biggest new mine in the world in over a decade. De Beers has no plans for another. ... The diamond business gained its sparkle around 1866, when a farmer’s son picked up a glistening pebble on the bank of the Orange river in South Africa. For most of the next 150 years, De Beers would dominate the global market. Success depended on manipulated supply and skilfully cultivated demand. ... Much has changed since then. De Beers can no longer control the market. Though it is the biggest producer by value, it accounts for only a third of global sales, down from 45% in 2007. It faces many uncertainties, from synthetic diamonds to changing relationships with polishers and cutters. Its loosening grip is reflected in increased volatility: its sales fell 34% in 2015, before bouncing back by 30% last year. Meanwhile the source of the demand that drives sales—the link between diamonds and love—looks weaker than it used to. ... But one forecast seems solid: there will be fewer new diamonds. ... diamonds’ principal value has nothing to do with science. ... They are a “Veblen good”, as items that gain their value solely from their ability to signal status are named, after Thorstein Veblen, an economist who wrote about the spending of the rich.