Two miners broke through a wall 300 meters beneath Mexico’s Naica mine in 2000, stumbling into a cavern where gypsum beams dwarfed a city bus. Researchers soon realized the flooded, magma-heated chamber had grown these crystals over 500,000 years in conditions deadly to humans.
In April 2000, two miners named Juan and Pedro Sánchez were digging a new tunnel about 300 meters underground in the Naica mine in Chihuahua, Mexico, when they broke through a wall into an unexpected chamber. The brothers worked for Industrias Peñoles, a company that had extracted lead, zinc, and silver from the mine for decades. The space they entered was shaped like a horseshoe and filled with m…