Inside the world's largest geode, which can contain at least six people at a time, you'll see crystals of 8 to 18 inches penetrating walls made of the bluish mineral, celestite.

Imagine walking through a dusty, arid landscape when you stumble upon a seemingly ordinary rock. Its rough exterior might not catch the eye, but what lies within surely will. Geodes are one of ...

As Mila Carretero, geologist and coordinator of the Pulpí Geode, explained, a geode is a cavity inside a rock that is covered with crystals. Sitting against a backdrop of oversized crystal spars ...

Geodes are hollow rock filled with dazzling crystals. I'm at the American Museum of Natural History in New York City and behind me is an amethyst geode that was formed millions of years ago.

Geodes are hollow rock formations often with quartz crystals, such as amethyst, inside. Amethyst geodes in Uruguay have been found in cooled lava flows, which date from the original breakup of the ...