On a visit to Tucson, relatives took me to a gem and mineral show where we saw a collection of geodes. Ordinary on the outside; beautiful on the inside. Will you please tell us how they are formed and ...

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 ...

The geological history that led to the formation of giant crystals and a 36-foot geode has been revealed by scientists. By looking at the abandoned mine where the geode of Pulpí was found, they were ...

Gabriela Farfan, the Smithsonian's curator of gems and minerals, answers the internet's burning questions about gemstones. Are all minerals crystals? How are diamonds cut? How do geodes form? Is the ...

Any geode might make us wonder: What geologic forces form these hollows lined with crystals? But the Pulpí Geode, discovered in an abandoned Spanish mine, takes wonder to a different scale. One of the ...