Agatized Coral?

[Major]

Found not in the creek, but actually near a Louisianan style restaurant called "Mimi's Cafe"

Title and Description ask it all:

Well, I guess not all of it. This is an odd section, pattern on the rock reminds me of crustaceans :/

(the white-ish section of course)

~Eric

[Frank Menser]

Where was this found? This looks a lot like material I have collected in the Gainsville, Florida area. Mostly a flint/chert type rock with some agate forming those "bubbles"(it's all quartz) plus a little limestone on the trim. Tyr scratching the gray rock with a knife blade. If it is chert it should not scratch as it has a hardness on Moh's scale of around 7 (steel is 5.5 as I recall). If the blade can scratch it you are probably just dealing with Limestone, but the presence of Agate makes that more unlikely.

I found one piece that actually had a echinoid imbedded in it. It is a sedimentary formed mineral, so you can't rule out the possibility of fossils.

[Major]

Where was this found? This looks a lot like material I have collected in the Gainsville, Florida area. Mostly a flint/chert type rock with some agate forming those "bubbles"(it's all quartz) plus a little limestone on the trim. Tyr scratching the gray rock with a knife blade. If it is chert it should not scratch as it has a hardness on Moh's scale of around 7 (steel is 5.5 as I recall). If the blade can scratch it you are probably just dealing with Limestone, but the presence of Agate makes that more unlikely.

I found one piece that actually had a echinoid imbedded in it. It is a sedimentary formed mineral, so you can't rule out the possibility of fossils.

Found next to a new retention pond.

The grey/white rock reacted to the knife, but barely. I can't place it. It's harder than average limestone, which makes me want to say dolostone, but it's coloration somewhat disagrees with me. Dolostone is usually white, light brown, or pink(ish)..

Image of the other side:

A trace fossil of a shell is evident on the right side of this image.

Sweet! Have a picture of it?

[Guest solius symbiosus]

The grey/white rock reacted to the knife, but barely.

Test it on a fresh surface.

[Harry Pristis]

Found next to a new retention pond.

The grey/white rock reacted to the knife, but barely. I can't place it. It's harder than average limestone, which makes me want to say dolostone, but it's coloration somewhat disagrees with me. Dolostone is usually white, light brown, or pink(ish)..

Image of the other side:

A trace fossil of a shell is evident on the right side of this image.

Sweet! Have a picture of it?

It's "Florida chert" or "Coastal Plains chert" to the artifact collectors. It is the stuff that Native Americans used to make lithic artifacts. It occurs within the Ocala Group Limestone. It is a nuisance to limerock mining operations.

Over the eons, as the limestone of the Ocala Uplift was eroded away, blocks and nodules of this chert were left behind on the surface.

As Frank pointed out, chert is a sedimentary rock, so it is quite possible to find fossils in it. In fact, these fossils (mainly forams) were the bane of NA knappers. The fossil inclusions often represent weak places in the chert which gave way during knapping.

Occasionally, you can find a vug filled with druzy quarts, but these vugs are small -- the size of the foram or other small organism that preceded it. Here's a point with a vug that the knapper worked around. The vug is lined with druzy quartz, though that is not evident in the image.

[Frank Menser]

Nice Vug!

[Major]

It's "Florida chert" or "Coastal Plains chert" to the artifact collectors. It is the stuff that Native Americans used to make lithic artifacts. It occurs withing the Ocala Group Limestone. It is a nuisance to limerock mining operations.

Over the eons, as the limestone of the Ocala Uplift was eroded away, blocks and nodules of this chert were left behind on the surface.

As Frank pointed out, chert is a sedimentary rock, so it is quite possible to find fossils in it. In fact, these fossils (mainly forams) were the bane of NA knappers. The fossil inclusions often represent weak places in the chert which gave way during knapping.

Occasionally, you can find a vug filled with druzy quarts, but these vugs are small -- the size of the foram or other small organism that preceded it. Here's a point with a vug that the knapper worked around. The vug is lined with druzy quartz, though that is not evident in the image.

Anyone ever tell you that you could talk bill gates into joining the military?

As always, thank you, and you've blown me away.

~Eric

[barefootgirl]

It's "Florida chert" or "Coastal Plains chert" to the artifact collectors. It is the stuff that Native Americans used to make lithic artifacts. It occurs withing the Ocala Group Limestone. It is a nuisance to limerock mining operations.

Over the eons, as the limestone of the Ocala Uplift was eroded away, blocks and nodules of this chert were left behind on the surface.

As Frank pointed out, chert is a sedimentary rock, so it is quite possible to find fossils in it. In fact, these fossils (mainly forams) were the bane of NA knappers. The fossil inclusions often represent weak places in the chert which gave way during knapping.

Occasionally, you can find a vug filled with druzy quarts, but these vugs are small -- the size of the foram or other small organism that preceded it. Here's a point with a vug that the knapper worked around. The vug is lined with druzy quartz, though that is not evident in the image.

Thats cool! Travis county actually found half a point today that had a vug in it lined with druzy quartz.