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Lori Garza
 #1 
Hi! I was wondering.. How do you Identify geodes? What do they look like before you crack them open? I live in Texas.
Mike Streeter
 #2 
Hi Lori,

Geodes are generally round or roundish hollow mineralized rocks that are distinct from the rock in which they form. Their surfaces are often irregular and knobbly, but can be smooth. They outer surfaces sometimes show veining, an indication of interior mineralization. Since their exteriors are harder than the rock in which they form, they are more resistant to weathering and erosion making them stand out in outcrop or even when mixed with other rocks when loose on the surface. With all this said, the best way to learn to recognize geodes is by experience collecting them. So, find a place where they are known to be plentiful, and go for it!

By the way - rocks that look and form like geodes, but are not hollow are called nodules or concretions.

Mike
gemhunter
 #3 
Hi Lori,

There is a new book out called Geodes Nature's Treasures by Brad Cross & June Culp Zeitner. It is a very well written book on Geodes and it has a lot of photos in it to showing what Geodes look like from different areas. KOR
maliya
 #4 
hello,

I was wondering how you can tell if it is a geode from the outside?
I was also wondering what kind of environment geodes grow in?
Mike Streeter
 #5 
As I wrote before, geodes are generally round or roundish hollow mineralized rocks that are distinct from the rock in which they form. Their surfaces are often irregular and knobbly, but can be smooth. They outer surfaces sometimes show veining, an indication of interior mineralization. Since their exteriors are harder than the rock in which they form, they are more resistant to weathering and erosion making them stand out in outcrop or even when mixed with other rocks when loose on the surface. In most cases, you have to crack or cup open a potential geode to see if it in fact hollow. Sometimes a geode will rattle if it is really how and there are loose pieces of rock or mineral inside. Geodes are also lighter than a concretion or nodule of the same size.

Geodes can form in gas bubbles in igneous rocks or in rounded cavities in sedimentary formations.

Mike
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