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.