Any geologist out there?

[JIMMFinsman]

I'm sure this is not a fossil but I have seen rocks like this. It's like a rock within a rock. Came out of the ocean in Delaware. 

[Mark Kmiecik]

Not an egg for sure. This type of layered rock is called a concretion. It forms around a core object, sometimes organic, in layers that accumulate over time. Mazon Creek fossils are an example of when the concretion forms around an organic core, either plant or animal.

[JIMMFinsman]

Thank you!!

 

[ClearLake]

This could be part of a concretion, it could also be caused by differential weathering or diagenesis of the rock.  Diagenesis is the change that occurs in a rock as it progresses from sediment to lithified rock.  Very slight variations in the rock chemistry can cause different colors to form as ground water moves through it.  Also, sometimes you get weathering rinds that form on rocks as they are exposed to the elements.  The outer part turns a different color or texture as weathering occurs and if the rock is broken open you may see differing bands of color but they form from the outside in rather than the inside out as is the norm for concretions.  Several different processes can form rocks like you found, sometimes its easy to tell which process occurred, sometimes not so much, especially when the rock is a fragment and as water worn as your piece is.  

[JIMMFinsman]

Very informative thank you!  There are soa many kinds of rocks and quartz that wash up every day. I have some weird types. 

[Tidgy's Dad]

Possibly eroded sandstone?