where are the largest crystals found on earth
Cave of the Crystals The main chamber contains giant selenite crystals (gypsum, CaSO4·2 H2O), some of the largest natural crystals ever found.[1] The cave's largest crystal found to date is 12 m (39 ft) in length, 4 m (13 ft) in diameter and 55 tons in weight. The cave is extremely hot, with air temperatures reaching up to 58 °C (136 °F)[2] with 90 to 99 percent humidity. The cave is relatively unexplored due to these factors.[3] Without proper protection, people can only endure approximately ten minutes of exposure at a time.[4]
Mineral There are over 5,300 known mineral species; as of March 2017[update], over 5,230 of these had been approved by the International Mineralogical Association (IMA).[2] The silicate minerals compose over 90% of the Earth's crust. Silicon and oxygen constitute approximately 75% of the Earth's crust, which translates directly into the predominance of silicate minerals.