Is It A Fossil Egg Or Is It A Rock?

[garybroz]

Hi

I live in eastern Massachusetts and a few years ago I installed a deck behind my house. I had to dig 12 holes 4 feet deep. The dirt was like concrete but I got it done, At the bottom of one of the holes I found an odd rock. It was oval in shape and cracked in half on its own. I had the other half, but it kind of crumbled, This half is still pretty solid. I kept it because it was cool and odd, and I have always wondered if it was just a rock or something more interesting.

So, I was hoping someone who knows more than I about these things might know.

Thanks in advance

Gary

[Raggedy Man]

Sorry, but its not an egg. It looks like a big concretion.

Paul

[Fossildude19]

Concretion, not an egg. Sorry.

Regards,

[garybroz]

Thanks for the quick answers.

No disappointment, I had cool rock before and I still do.

Now I know a little more about it than I did.

Thanks

[Auspex]

I can see why you kept it.

It is not, unfortunately, an egg. For that, we look for particular textures on a thin shell, and for polygonal fracturing when they are distorted by geologic forces.

Given the concentric structure, yours looks to be a concretion of sorts.

[garybroz]

Any idea what it might be a concretion of? It was a very clayish soil.