Fossil and rock identification

Evo

Definitely not a sponge (cnidarian).

http://www.google.com/search?aq=&rlz...og&sa=N&tab=wi

phlip180

I can't tell if it's just the angle the picture is taken from, but it looks like the holes are more concentrated in certain areas than others. Is that an accurate assessment or am I just imagining things?

Evo

I'll try to get better pictures from all angles. Yes, the holes are not over the entire rock. I just found a large boulder that has a lot of little "pockmarks" all over it, but nothing like the holes on this rock, I'll get more pictures this week, we're expecting severe storms tomorrow.

phlip180

I have seen a lot of rocks like that in Missouri. I've noticed they tend to be, or come from, large boulders. Since they're sedimentary and found in the midwest, I assume they were probably formed during the Mississippian Period, when the midwest was underwater. That's all I know about them so far, and you might have already known all that, or have a different theory. I'm going to a nature center this weekend, so I'll do a little research while I'm there.

dlgoff

I was tamping the dirt around some fence post in preparation to re-stretch the wire when I heard a clank. This is what I pulled out of the ground. It's about 4 1/2 inches long and weights about 10 ounces. I checked with a magnetic, but it's not ferrous.

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Evo

Bigger pics? You can send me the files.

dlgoff

Done. Thank you.

Evo

I've seen that weird yellow-orange stuff coming out of rocks before, but I'll have to look again.

I'm so disappointed that so many fossils and fossil rocks posted online either have no pictures or just black and white drawings, many just have a written description, which is SO ANNOYING.

dlgoff

That yellow-orange stuff is very hard which was surprising to me and after looking even closer, could be something fossilized. And from the weight, I thought it surly had iron in it.

Thank you for looking.

Andre

Any progress? The bluish greenish hue may indicate copper. Have you considered bornite or maybe chalcite

Just my

chemisttree

It looks like a fine-grained slate or shale but it could also be a basalt. The dark color of the fracture surface suggest it could be a mafic basalt or pyroxene. The orange could be manganese compounds (manganese oxide is orange) or iron oxides, both present in mafic basalts. If you look closely at a freshly fractured surface do you see small white veins of mineral? Just to the west of where I live near San Antonio is an intrusion of basalt that is richly veined with magnesium compounds. When mined and processed into gravel, piles of this material leach out the magnesium when it rains producing puddles of white magnesia everywhere.

Evo

DL sent me more pictures, they are actually light colored stones and the "blue" color was a problem with the camera lighting.

chemisttree

Is the fracture surface also light?

dlgoff

The light was from one of those CFLs causing is to appear bluer than it is. Here's two taken in sunlight.

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chemisttree

Now it looks like a fossilized rhino horn! So I take it the fresh fracture surface (facing down (!) in both pics) is light colored in the brighter light?

dlgoff

Actually it's cross section is more triangular shaped.

Side 1



Side 2



Side 3 (bottom)

ngruman

Your "swimming yams" look like rip-up clasts from some sort of flow - based on how they are aligned. Do you happen to know what the matrix is surrounding the yams? And what are the yams made out of?