Never found one like this

[GaRelicHunter]

I found this in North GA near Rome GA.

 

I don't know what this is, but it has to be something.

 

 

[Rockwood]

I'm afraid it may be banded chert.

[GaRelicHunter]

4 minutes ago, Rockwood said:

I'm afraid it may be banded chert.

 

Do the bands on banded chert raise up? Look at this thread of the little one in the last photo, they look the same, the ridges on this new rock can be felt also but they aren't as tall

 

[Rockwood]

I doubt it would be diagnostic. Someone better qualified to say more will be along soon.

[TqB]

Banded chert was my first thought too. I'm more familiar with European banded flint from the Chalk and the bands are often in raised relief. Try "banded flint" images search.

[Fossildude19]

Banded flint example; 

 

[ynot]

The minerals included in the "bands" will differ in quantity and mineral included. This will make some layers more susceptible to erosive conditions, and will give the ridged appearance to it.

[abyssunder]

For both topics, my proposal would be the dissipative concretionary overgrowth resembling Westerstetten pattern.

 

"At a much smaller scale, chert concretions in Cretaceous and Tertiary chalks of North Africa (Fig. 9(a) and (b)) are commonly overgrown by chert layers of similar configurations. There is also a certain symmetry between pancakes on the upper and lower side of the nodule, as in Marleik concretions (Fig. 7). Since such overgrowth has never been observed in the millions of chert nodules washed out from the chalk cliffs of Northen Europe, we probably deal with an epigenetic overgrowth caused by silica mobilization under arid conditions. A climatic control is also likely for the Westerstetten karst system, which formed during warm Cretaceous and Tertiary periods, as well as for the Liesegang Rings in Petra sandstones (Fig.3). Nevertheless the rhythmicity of these patterns is probably intrinsic, rather than reflecting climatic or seasonal cycles. " - A. Seilacher

 

excerpt from A. Seilacher. 2001. Concretion morphologies reflecting diagenetic and epigenetic pathways. Sedimentary Geology 143:41-57