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Identity HelpMay be feldspar and flint.

9th Sep 2019 15:08 BSTLarry C Eicher

Sirs:  I need ID confirmation for this rock.  I picked it up in a local stream bed in December about 10 years ago.  I ran it through  week of course tumbling and removed it when I saw it cleaned up.  Locality is Richland Co., Ohio, USA.


9th Sep 2019 15:22 BSTPaul Brandes Manager

Well, flint is slightly harder than feldspar, so a hardness test should distinguish. To me, it looks like a piece of chalcedony.

9th Sep 2019 15:57 BSTAlfredo Petrov Manager


11th Sep 2019 14:14 BSTEd Clopton Expert

Looks like chert to me.  The pattern of coloration, the smoothly curved fracture surfaces, and the lack of distinct cleavage where it is broken argue against feldspar and are all characteristic of chert.  Chert is a well-defined rock type; "flint" is an informal term that usually refers to grey or black chert found as nodules in limestone.  Chert would be at home in the sedimentary rocks of Ohio, but anything found in Ohio also could have been transported by glacier from somewhere/anywhere Up North.

11th Sep 2019 20:48 BSTRobert Nowakowski

How about hardness?  

16th Sep 2019 17:24 BSTLarry C Eicher

I'm sorry that I cannot find the sample.  I must have given it to a grandchild but none of them own up to it.  I guess I must proceed without knowing hardness.

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