Naica Project - a mining operation principally for lead. The major operation uses huge pumping units to de-water sections of the mine for lead mining. In 1910 within this complex a 250 foot long chamber was discovered which contained beautiful selenite crystals up to 6 feet long - easily the largest and finest gypsum crystals ever found. In fact, at a depth of about 360 feet, the walls were covered with them. This site was named the Swords' Cave.
In April of 2000, at 1000 feet below ground level, three more such chambers were discovered. These locations were named the Queen's Eye Cave, Candle's Cave and the most spectacular of them all, Crystal's Cave, where selenite crystals in some cases 30 feet long and as much a 4 feet in diameter are scattered around like common pick-up-sticks. What has water got to do with this you say?
It's in the formation. According to the website:
"These macro crystals formed underwater in the area where sulphide saturated phreatic thermal waters (52°C), came in contact with oxygen-rich cold waters, naturally infiltrating from the exterior. The surface and subsurface waters could not mix due to the density of the phreatic mineralized water; oxygen diffused into the lower layer, resulting in the oxidation of sulphide ions to sulphate which caused an extremely light over-saturation of gypsum and therefore a slow deposit. These singular conditions prevailing for hundreds of thousands of years created a mineral wonderland, a site of scientific interest and an extraordinary phenomenon."
Another amazing story of the wonders of water. And speaking of water, the clime inside this cave is brutal on humans. It remains about 45-50 degrees C and close to 100% humidity. People can only tolerate these conditions for 10-15 minutes at a time normally - and up to about 30 minutes with special clothing and gear. Kind of sounds like Texas in the Summer, if you ask me!