Giant Crystals Found Inside Mexico's Naica Mine

Nestling up to a cauldron of pressurized, molten rock is almost never a good idea. But in Mexico's Naica mine, the payoff is worth the risk. About 900 feet below the surface, there is a chamber filled with gypsum. It's the same stuff that goes in the drywall in your house, only in Naica it spent half a million years parboiling in a chamber filled with magma-heated water.

Suddenly miners showed up and started pumping the mineral-rich broth out to get at valuable silver and lead deposits nearby. The result is a cavern filled with crystals 36 feet long and weighing in at up to 55 tons, easily the largest in the world.

Last Fall, adventurer and filmmaker George Kourounis traveled to Naica to see the incredible “Crystal Cave of Giants” for himself. Though there's little risk of eruption from the nearby magma chamber, the cave itself is still deadly hot – over 120 Fahrenheit with about 90 percent humidity. People are only allowed in without cooling suits for a few minutes at a time. Sadly, once the silver in Naica runs out, miners will likely turn the pumps off again. The chamber will fill with water, the crystals will once again be among Earth's vast, inaccessible depths. The cave itself is still deadly hot, over 120 Fahrenheit with about 90 percent humidity. People are only allowed in without cooling suits for a few minutes at a time.