Please help identify this rock

It's a concretion. The dictionary definition :

Geology . a rounded mass of mineral matter occurring in sandstone, clay, etc., often in concentric layers about a nucleus.
thanks to dictionary.com

I'm actually kind of proud of myself....I haven't use much geology in ages and this was the first word I thought of. It looks more "rock" than "crystal", so didn't think it was geode. Same basic process as an agate, but with the concentric so very, very round, concretion is the further definition.
I thought "petrified lemon", too.
And Gobstoppers are created the same way, albeit much sweeter and quicker.

reply to post by stars15k


I did a goggle search on concretion, and I think that you might be right....But still can't find one that oloks similar to this.

Thank you..

reply to post by VeniVidi


You have a very nice example. You should take it to a rock, mineral, and fossil show....there would probably be some interest, since it's so very symetrical. Putting a polish on would make it look very cool and probably bring out the colors.

I found this picture at trailsventurebc.com:

[atsimg]http://files.abovetopsecret.com/images/member/36d50dc7cc44.jpg[/atsimg]

I searched using "geologic concretion". See what I mean about your's being a nice example? Lots of layers, with lots of colors, and nicely round. It must be very old, or very well traveled to produce the layers it has.

reply to post by stars15k


I have never polished a rock before. Someone gave me so info above, and I will do some research on it.
Thanks again