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?

Amethyst is one of the most abundant crystals in the world, but the most prized pieces can cost almost a million dollars. Some of the world's largest amethyst geodes come out of Artigas ...

Pennsylvania may not be the first place that comes to mind when thinking of gemstone mining, but the Keystone State has a surprising diversity of beautiful natural gemstones that can be found across ...