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?

YEKATERINBURG, December 29. /TASS/. A Russian dolerite crystal, Oil Drop, is claiming the title of the world’s biggest. Russia’s Yekaterinburg-based Jewelry House has filed an application with ...

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 ...