Plain ole rock or possible egg?

[ChaYa]

I went home to help clean out my family storage unit. While home I found a rock that resembles an egg. I used to do landscaping in Illinois and I believe that's when I found it. I haven't looked at it in over 20 years. When I saw it again it made me curious. The lines on it do look like breakage and the most interesting part to me is that it has indentations on both sides which makes me think it was soft at one point. Also, on the rock seems to be compressed into an elongated shape which coincides with the indentations. Its about 7 inches in width and about 8.5 inches in diameter. It seems to be slightly porous under close examination. The open end leads me to believe that its not an egg but some of the smaller cracks that are raised look similar to shell. I appreciate everyone taking the time to look at it.

[Randyw]

I could be wrong but I think you were right in your description of it as a rock that resembles an egg.

[Fossildude19]

Concretion, would be my vote. 

Have a look through our egg guides... 

[Mark Kmiecik]

+1 concretion. Concretions have a habit of looking like eggs. Oval rocks are EXTREMELY common. 

[Ludwigia]

+2 for concretion.