Cave of the Crystals

Cave of the Crystals or Giant Crystal Cave is a <a href="/facts/Cave/SNfJTJtM">cave</a> connected to the <a href="/facts/Naica_Mine/oYr4mPnq">Naica Mine</a> at a depth of 300 metres (980 ft), in <a href="/facts/Naica/XHHmH2Cl">Naica</a>, <a href="/facts/Chihuahua_(state)/FCeDVWL0">Chihuahua</a>, <a href="/facts/Mexico/IT5bwhdh">Mexico</a>. It takes the form of a chamber within the <a href="/facts/Limestone/8ntvtFnR">limestone</a> host rock of the mine, and is about 109 metres (358 ft) long with a volume of 5,000 to 6,000 cubic metres (180,000 to 210,000 cu ft).
The chamber contains giant <a href="/facts/Selenite_(mineral)/ChMIJw4P">selenite</a> <a href="/facts/Crystal/e2R2mk3E">crystals</a> (<a href="/facts/Gypsum/MItYU70n">gypsum</a>, CaSO4 · 2 <a href="/facts/Water_of_crystallization/sbaKJNJX">H2O</a>), some of the largest natural crystals ever found. The largest is 11.40 metres (37.4 ft), with a volume of about 5 cubic metres (180 cu ft), and an estimated mass of 12 tonnes. When not flooded, the cave is extremely hot, with air temperatures reaching up to 58 °C (136 °F) with 90 to 99 percent humidity. This is comparable to temperature records in <a href="/facts/Death_Valley/VLvcwx4t">Death Valley</a>, but with much wetter air that results in a much higher <a href="/facts/Wet_bulb_temperature/sBdoylUX">wet bulb temperature</a>; this prevents cooling via sweating. The cave is relatively unexplored because of these factors. Without proper protection, people can only endure approximately ten minutes of exposure at a time.
The cave was discovered in April 2000 by brothers Juan and Pedro Sánchez while drilling in the mine. As of October 2015<a href="https://en.wikipedia.org/w/index.php?title=Cave_of_the_Crystals&action=edit">[update]</a>, the mine had reflooded and the cavern filled once more with the water rich in minerals required for the crystals to grow.
A group of scientists in the Naica Project have been studying these caverns.

Cave of the Crystals open-in-new

Cave of the Crystals