Geodes, crystals bursting out of a rocky shell ... and tiny crystal layers form inside the rock-bubble. As layers upon layers of mineral-water-turned-crystals form over thousands or millions ...

After guiding us through a small museum behind his office, Kirk Brandenberger of the Keokuk Area Convention and Tourism ...

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?

Large crystals found in geodes and other rocks are relatively rare. Pink ChalcedonyA pink chalcedony shows off its beauty. Chalcedonies include many types of cryptocrystalline quartz gems and ...