Discovered in 1999 inside an abandoned mine in Southern Spain, Pulpí Geode is the largest crystal 'cave' of its kind in the world. But what exactly is a geode and how do crystals form inside them?

All the Latest Game Footage and Images from Crystal Chip Collector: Hidden Gem "Crystal Chip Collector: Hidden Gem" is a fast-paced platforming puzzle game with a neo-retro style. Collect all the ...

This is how scientists believe Crystal Cave was formed. And if you go to Put-in-Bay, you can tour the island's geode for yourself. Read more: 25 Gorgeous Islands For Vacationing That Won't Break ...