Deep below the Chihuahua desert in Mexico, connected to the Naica silver and lead mine, lies the Cave of Crystals. Discovered in 2000, it contains some of the largest crystals on Earth. The cave is warmed by magma below, and temperatures of 50+ celsius and near 100 percent humidity necessitate protective equipment when exploring the cave. The crystals are made of selenite, and can be up to 11 m long. National Geographic:
For hundreds of thousands of years, groundwater saturated with calcium sulfate filtered through the many caves at Naica, warmed by heat from the magma below. As the magma cooled, water temperature inside the cave eventually stabilized at about 136°F. At this temperature minerals in the water began converting to selenite, molecules of which were laid down like tiny bricks to form crystals. In other caves under the mountain, the temperature fluctuated or the environment was somehow disturbed, resulting in different and smaller crystals. But inside the Cave of Crystals, conditions remained unchanged for millennia. Above ground, volcanoes exploded and ice sheets pulverized the continents. Human generations came and went. Below, enwombed in silence and near complete stasis, the crystals steadily grew. Only around 1985, when miners using massive pumps lowered the water table and unknowingly drained the cave, did the process of accretion stop.(via reddit)
Unsere Erde ist schon ein erstaunlicher Ort…
