Mind-blowing giant crystals--what can they teach us?

Giant gypsum crystals--some of which are in excess of 30 feet long and half a million years old--are found deep within the Naica mine in Chihuahua, Mexico and are renowned for their spectacular beauty. While large gypsum crystals can also be found at sites around the world, such as Segóbriga and Pulpí in Spain, and the El Teniente mine in Chile, Naica boasts the most exceptional ones.