In addition to the obviousness of the argument, there are also some examples to compare to real objects:
http://geology.about.com/od/more_sedroc ... enesee.htm
As you can see, this concretion also expanded. Likely during the Z Pinch process as extra material was created, or gathered, pushing the 'crust' off it.
The concretion you link to is a perfect example of what I've stumbled across the past two weeks.
I mentioned in another thread falling down the rabbit hole and finding everything that discusses "biological transmutation". Essentially, the Universe is a vast machine manipulating matter, transmuting it; shaping it, growing matter everywhere, even as we speak. That things like Low Energy Nuclear Reactions are occurring on a regular basis; biological, non-biological, etc... That's how the Earth grew, the planets, everything.
That's why dating using radioactive sources is not accurate since all the elements are endlessly mutable. It seems even something as simple as water can act like a machine transmuting elements.
Start with the key post in Recovered: Transmutation on Stars, Planets etc
and then read the whole thread, and follow all of the links to see what I mean. It will take you a couple of intense weeks, but it will add the foundation to understand how matter comes into existence rather than "from nothing".
When I reached a stopping point, and essentially ran out of steam, I realized that all the SciFi stories of nanotechnology growing things from "seeds" already exists, and it's called the Universe.
I've got to go have a lie down now, my brain is melting. Wait, it's not melting, it's transforming into a Crystal Skull--Noooooo!
I'm having too much fun with all this.