Just 200 km (124 miles) south of the Arctic Circle, Canada's Ekati Diamond Mine, operated by BHP Billiton Diamonds Inc., is one of only two diamond mines operating in North America and the first to combine open-pit and underground mining. Its first diamond was recovered in October 1998. Today, the mine processes more than 10,000 tons of ore per day, producing four to five million carats of rough, gem-quality diamonds each year. This represents nearly 4 percent of current world diamond production by weight and 6 percent by value. But it doesn't come easily.