Crystals like those in Cueva de los Cristales form when hot, mineral-rich water fills underground cavities and remains undisturbed for a very long time. In the case of this cave, the water was ...

The Smithsonian’s National Museum of Natural History has acquired the 2.33-carat "Winston Red Diamond," as part of the “Winston Fancy Color Diamond Collection.” ...

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?