The limestone cavern and its glittering beams were discovered in 2000 by a pair of brothers drilling nearly a thousand feet below ground in the Naica mine, one of Mexico’s most productive, yielding tons of lead and silver each year. The brothers were astonished by their find, but it was not without precedent. The geologic processes that create lead and silver also provide raw materials for crystals, and at Naica, miners had hammered into chambers of impressive, though much smaller, crystals before. But as news spread of the massive crystals’ discovery, the question confronting scientists became: How did they grow so big?
I remember when this was first discovered, and how blown away I was when photos were released of this magnificent wonder. There’s a documentary out there called, “Naica: Beyond The Crystal Cave” and another that hits on other sister caves as well, “Into The Lost Crystal Caves”. Definitely interesting if you want to watch them go through the cave to get samples and explore. A dangerous but extremely satisfying task! Here’s a bit of information on the Crystal Caves in Naica, Mexico.
It contains some of the largest (in size, mass, length, etc) natural crystals ever found on Earth. A Gypsum beam was found to be 11 metres (36 feet) in length, 4 metres (13 feet) in width, and weigh around 55 tons.
It is found in a horseshoe-shaped cavity of limestone rock, which used to be full of mineral-rich hot water, but has since been kept drained.
The cave is extremely hot with air temperatures reaching up to 58 °C (136 °F) with 90 to 99 percent humidity.
The cave was filled with mineral-rich hot water (a constant 50 °C+) for around 500,000 years, which let these crystals form under the right conditions.
I’ve added a few links that take you to more photos and articles as well (along with its sister caves).