split rocks

[Roberta NJ CA]

I found this rock many many years ago.  I called in my California baked potato due to it's shape and color.   It had a natural "thumbprint" indentation so I placed my thumb on it and banged it on the bottom side of it and it broke open rather easily in two parts.  Inside each half was a mirror image of the other... when I placed them back together in it's original form I lined them up,  and curled it open I thought "Oh, it's a fossil  butterfly, how cool!" I remember taking it to a local rock shop where I was told "No, it's nothing just the inside of a rock - that's it "   I was somewhat discouraged but still thought it to be unique.  I have used the rock (untruthfully) to explain what a fossil looks like to my nephew to explain fossils (yikes)  - but it does serve to get a picture in his mind.

 

  It serves as a reminder as to the "kindness" of the numerous educated members here who are asked to ID something (which could be "nothing:) -  by never undermining or embarrassing those who come here for information on what they have found to be something "special" THEY have found - I know this from experiences and Kudos to you all!!  Anyway I do know this is NOT a butterfly, perhaps a leaf, or maybe just the inside of a rock - let me know what you think!

 

 
 
 

 

[ynot]

What You are seeing is called "hackle fringe".

It is the way some rocks will break when hit hard enough.

Not a fossil.

[Roberta NJ CA]

Thanks Tony, didn't think it was but loving the id - 'HACKLE FRINGE"!! 

[caldigger]

27 minutes ago, ynot said:

What You are seeing is called "hackle fringe".

It is the way some rocks will break when hit hard enough.

Not a fossil.

Agree, however it is a rather nice pseudo fossil example.

[Tidgy's Dad]

It's a nice and pretty object. 

And a very nice story too, thanks for sharing, Roberta. 

 

[Rockwood]

Looks like it fractured along what is essentially a single liesegang band.

A poorly preserved ginkgo leaf would look quite similar.

[Scylla]

4 hours ago, Rockwood said:

Looks like it fractured along what is essentially a single liesegang band.

A poorly preserved ginkgo leaf would look quite similar.

I was just going to say it had a superficial resemblance to a ginko leaf but that I agree with fracture.

[Herb]

very cool looking

 

[Ludwigia]

This is actually quite typical for many concretions. The outside layer of the "egg" being softer and lighter colored due to the influence of weathering and the inside being darker and more compact and dense.

[minnbuckeye]

You could call it a jellyfish just like those Mazon Creek collectors who label any of their nondescript nodules this. And yes I am just yanking the chain of those who collect Mazon material. With that said, it does require expertise when examining opened nodules. I could easily throw out a Tilly Monster into the discarded rock pile without an understanding of the material. But now that the experts look to be calling this a rock, a nice one at that, enjoy it for what it is!

 

Mike

[Steve]

hackle fringe is a new one on me.Surprised a crystal power dealer isn't selling rare hackle fringe stones for only $59.99 each.By the way does anyone want to buy one?Restore your energy flow have more energy all that good stuff..........Steve

[Roberta NJ CA]

Thanks to all who took time to look at my "pseudo ginko leaf Hackle Fringed Tilly Monster!"