Large scale open-pit mining takes millions of gallons of water, mostly to dilute the cyanide used to soak the ore and separate its microscopic bits of gold. About 20 of Nevada’s major gold mines may not last much longer than 2015, but that’s when the biggest problems will begin. The vast pits they leave behind will create a deficit in the aquifer, and scientists estimate it could take 200 years or more to replenish the groundwater. Did I mention that to make one gold wedding band, about 20 tons of earth must be excavated?