From National Geographic: “In all of history, only 161,000 tons of gold have been mined, barely enough to fill two Olympic-size swimming pools.”

Like many of his Inca ancestors, Juan Apaza is possessed by gold. Descending into an icy tunnel 17,000 feet up in the Peruvian Andes, the 44-year-old miner stuffs a wad of coca leaves into his mouth to brace himself for the inevitable hunger and fatigue. For 30 days each month Apaza toils, without pay, deep inside this mine dug down under a glacier above the world’s highest town, La Rinconada. For 30 days he faces the dangers that have killed many of his fellow miners—explosives, toxic gases, tunnel collapses—to extract the gold that the world demands. Apaza does all this, without pay, so that he can make it to today, the 31st day, when he and his fellow miners are given a single shift, four hours or maybe a little more, to haul out and keep as much rock as their weary shoulders can bear. Under the ancient lottery system that still prevails in the high Andes, known as the cachorreo, this is what passes for a paycheck: a sack of rocks that may contain a small fortune in gold or, far more often, very little at all….

Even at showcase mines, such as Newmont Mining Corporation’s Batu Hijau operation in eastern Indonesia, where $600 million has been spent to mitigate the environmental impact, there is no avoiding the brutal calculus of gold mining. Extracting a single ounce of gold there—the amount in a typical wedding ring—requires the removal of more than 250 tons of rock and ore.