Featured Rock Specimen

Any idea what it is?
Thanks

 

Could be an enhydro agate or a number of other stones.

 

Looks like chalcedony. I've found some similar pieces in Arizona

 

I think maybe perhaps I've been watching too much Dr. P. Popper...

 

I think the underlying rock is lava, which leads me to believe that the top material is obsidian. Here is an example of pearl obsidian. Nice rock by the way.

 

Too funny......not haha.....I was just looking at Christie's Jewelry Auction and one of the pieces for sale is Obsidian!!!!! So coincidental!!!! Sure is a different looking rock Kard!!!! And it sure looks like there's lava involved somehow, but I definitely do NOT know enough about THAT!!!!! OR it's someone's miniature petrified intestines!!!!!

 

Any idea how were those formed?

 

It's definitely agate/chalcedony - which forms/formed from silica rich water/fluids flowing through cavities in the volcanic rock and slowly depositing/microcrystalizing into what you see there. It's almost what's considered "botryoidal" - forming/appearing like clusters of grapes.

https://www.google.com/search?rlz=1....1....1..gws-wiz-img.......0i7i30.051hFwiURjU

 

...botryoidal... Almost. Not quite.

 

Yeah... but it's in that general form.

 

I'm always threatening my wife that I'm going to quit working to become a rockhound and fossil hunter.

 

Where do you live? There are many locations still open to the public,but many more are closed due to property owners and insurance companies.

 

Well, that's another part of the problem, Holly. I live in northeast Ohio. Rock specimens are kind of out. But since this area was under a shallow sea millions of years ago, there are a lot of marine fossils. Actually, to my west, there is a town called Sylvania. They have Silica Shale cliffs from the Devonian Period. They used to have a "fossil park" where they would put piles of that shale out for people to pick through.

Took the family there years ago and the piles were a disappointment. As we were leaving, I decided to explore around the parking area and found a lot of decent specimens. A couple of small trilobites, horn coral, and many others. So, all in all, it was a great day!

 

Now this is botryoidal:



https://www.liveauctioneers.com/ite...m&utm_campaign=20190209rocks_ded#&gid=1&pid=1

 

Hi Bronwen,
That is a beautiful specimen!!!!!
greg

 

Botryoidality at its finest.