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Geology/Rock Indentification


Micro Geode???
Micro Geode???  

Red-Gray clay
Red-Gray clay  
I found this little rock in my farm (picture 1), inside a green-blueish sediment layer. Is it a geode? Also very close to this layer, among some other weird stuff, there is some kind of gray-red clay layer (picture 2), could you please tell me what it could be. Thanks a lot...

Hi Luis,
Good deduction!  Picture one is indeed a geode.  It's hard to tell but it might be a quartz geode.

As for the other looks like a very fine grained sandstone with some iron staining.  The iron staining is probably from microscopic iron minerals that were carried through the rock by groundwater.

Hope this helps.



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C. Robert Reszka, Jr.


I can answer any general geology question (rocks, minerals, stratigraphy, geomorphology etc.). My expertise is in the geology of the Michigan Basin, PreCambrian, Paleozoic and Recent. I can answer questions concerning mining and petroleum exploration and production and the laws concerning those activities. I can also answer questions concerning stratigraphy of the Michigan Basin. I will also answer questions about mineral and rock collecting in the Basin. I won`t be able to answer many specific questions on hydrology, geophysics or geochemistry. I may be able to answer very general questions in those venues.


I have been working for the State of Michigan for 36 years as a Geologist and a Resource Analyst. I have experience with Subsurface Geology and Petroleum Geology, mining in Michigan, and Sand Dune Mining and Protection issues.

Michigan Basin Geological Society

Decade of North American Geology.
Bedrock Geology of Michigan

BS Wayne State University

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