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 ...

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 ...

You bet. There are a 9,000-pound amethyst geode from Uruguay, a crocodile fossil from Germany, a sandstone formation from France and fluorescent minerals from New Jersey. Not to mention the ...