Egg rock from NE OHIO

Haven't seen any with anything like clay on the inside, but if there were they would never have been cut, polished, and sold in various rock shops. The inside is usually lined with quartzite crystals and are called geodes. Are you anywhere around Keokuk, Ohio?

Keokuk Ohio must be really small.....cant even find it on the map. The rock Im talking about has no crystals inside. Very common around here. Hard shell soft chalky material inside.

Got any photos?

Sorry. Maybe it's really in Iowa.

https://www.dropbox.com/s/t9mfd8kfahuk2dn/Egg%20rock.jpg?dl=0

It looks like a rock which has been in a stream bed for a long time (water smoothed). Do you have any photo's which show the interior? How thick is the "shell" layer? How hard is the shell layer compared to the interior? Are there color differences between the shell and interior?

My only thought so far is that it might be some form of clay nodule which developed a "shell" from exposure to something (Sun, Heat, Cold, Chemicals?)?

I would have to crack it open to see the interior. It is such a perfect shape, I hate to do it. Alot of our rocks around here are smooth. It was excavated from a basement on a hill.

These clay nodules are common around here. If I were to guess about the interior it would be chalky with a ferrous red / orange color

Don't crack it on my account if you don't want to. I thought you said there were lots of these things... I figured you could find another to crack open.