In the recent 2000 in the Mexican desert of Chihuahua (born Chihuahuan), at a depth of 300 meters was discovered unique cave's largest crystal in the world (English Crystal Cave of the Giants). This cave is in the Shaft complex called Naica and is located at an altitude of 1385 meters. For the first time this cave was discovered by geologists in 1794, but at that time it was used only as a mine for the extraction of silver, lead and zinc. Entering the Mexican Revolution (1910-1917 years) had to shut down the mine. It was only in 2000, researchers Juan and Pedro Sanchez stumbled on it and started to drill.
What they found at a depth of almost 300 meters, hit them. Incredible size and fantastic beauty gypsum crystals up to fifteen meters and almost one and a half meters in diameter, they are completely covered with the cavity of the cave. Each of these amazing crystal weighs about 55 tons and is considered by geologists, was formed at the junction of thermal (52 degrees Celsius) and cold water saturated with oxygen and sulfide over half a million years ago.
The main condition for the formation of these giant crystals is the unique climate of the cave, the main characteristics of which are: the air temperature is 50 degrees Celsius, humidity 90%, and high levels of hydrogen sulfide in the air. Without special equipment and costumes, cooling the air you breathe and the body, a person can survive in a cave no more than 10-15 minutes.
It is worth noting that in the future, after the research and development of this field will once again flood the mine with water, because it is constantly pumped her out — a very expensive undertaking.