Crystal Cave / Naica, Chihuahua, Mexico / photographic timeline
In this extraordinary (selenite) crystal cave, there are fissures in the bedrock that are heated by magma flows two to three miles below. With no natural entrance, this is a bubble inside the bedrock. This is what has helped to grow the crystals to such gigantic proportions. The caves are at 100% percent humidity, with the temperature about 120-150 degrees (Fahrenheit).