What Is It???? (I have a theory.)

I discovered this rock in my dad’s rock pile and I had no idea what it was … except that it was a chunk of agate.

(I use the term “agate” for most of the rocks my dad found in the desert. To me, that means it is a form of microcrystalline silica but it’s not jasper.)

The outside had a texture that reminded me of dino bone, but it wasn’t quite right for dino bone. Since my dad picked up a lot of dino bone, I’ve seen a lot of it and I know what it looks like.

I was curious enough to break out my wet angle grinder and polish down one side just to be able to see what the interior really looked like. (Note: the surface is not “polished” as my dad would have used the word in this picture. It’s just sanded down with a fine enough grit to see it clearly. I also know what a rock polish looks like and this isn’t it.)

Here are my conclusions so far:

• It’s some kind of fossil. Exactly what, I don’t know. But I have a theory. Nodules and seam agate have random markings. The interior of this rock is a replacement of something. I think it’s a replacement of something organic.

• The colors and some of the markings remind me of dino bone. But dino bone has regularly spaced cells and this piece just doesn’t have them.

• It’s not seam agate like Pigeon Blood, Graveyard Point, or Marvy because there’s no matrix. All seam agate I have seen has attached material of the rock around it. This rock appears to have an outer surface that reflects whatever it was originally, like a fossil “cast”.

• The top and bottom surface are different. The top has deep “wrinkles” and the bottom is rough, but not wrinkled.

• The thickness is relatively uniform. It seems to be a chuck broken from a larger “sheet like” piece. There is a sort of “layering” of the interior, seen best from the sides rather than the end that I polished, but it’s not at all “banded” like it would be it if was a traditional agate “cast”.

So … What is it? Here’s my non-scientific, amateur guess: I think it’s petrified dinosaur skin.

I say “dinosaur” in the most generic sense. In this context, it only means some kind of animal that lived during the great age of dinosaurs. They’re very rare, but fossils exist of just about all the parts of animal bodies from that age, not just their bones. I have another agate fossil that I think is a section of horn. It was found right there where all the dino bone was also found.

This would account for the layering that is not banding.

It would account for the interior structure that is not bone but looks like an organic replacement.

It would account for the relatively uniform thickness. Animal skins are organs like that. It would account for the wrinkled top and the rough, but not wrinkled bottom.

The thing coming in from the right side could be a healed wound of some sort.

What do you think?

Addendum -- 18 Dec 2023

My friend Ken -- He's contributed some of the best rock pictures here. -- made a great point that I thought deserved a place in the actual blog. Ken basically wrote that "coprolite is petrified soft squishy organic stuff -- so it must be possible'.

Great thought Ken!

I'm not bonded to the idea that it's "dino skin". I just believe people should keep more of an open mind and not leap to old ideas without good reasons.

I have several scientific papers that basically say, "nearly all the stuff that people think is coprolite .... really isn't". But these same papers DO say that petrified crap DOES exist in a very few cases. Maybe it is coprolite.