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 ...

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?

Geodes can be opened at Clint's shop in order ... King can only be obtained by unlocking Mining Mastery in the Mastery Cave.

The three-meter tall amethyst geode - a hollow rock filled with amethyst crystals - is the main attraction at the Crystal Caves at Atherton, southwest of Cairns. But it's now missing a bit after a ...