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Liberating Calcerous Fossils?


Paperstraw

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Hello,

I'm kind of frustrated right now. I've been attempting to extract the fossils from a piece of test limestone (Devonian, Moberly Formation) I collected in the fall. I've been placing small pieces into different concentrations of muriatic and acetic acid seeing what was the best. The test pieces dissolved and no fossils were present.

I decided to go full steam ahead with the test piece and dunk it into acetic acid (muriatic was way to reactive). After checking on it a few times the rock was dissolving and the fossils were fine. I decided to leave it for a few hours (read: sleep) and when I checked on it next most of the detail on the fossils had dissolved. So that shows that the fossils are calcerous in origin.

So now I ask, what is the best way to chemically extract these pieces without damaging the fossils, or will I hve to mechanically extrct them?

post-7633-0-80993100-1325633376_thumb.jpg

Edited by Paperstraw
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Any method that comes to my mind involves tedium...

"There has been an alarming increase in the number of things I know nothing about." - Ashleigh Ellwood Brilliant

“Try to learn something about everything and everything about something.” - Thomas Henry Huxley

>Paleontology is an evolving science.

>May your wonders never cease!

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the rule of thumb is that if the matrix and the fossil are made of the same stuff, then fade ten and punt.

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If these are sports analogies, the meaning is lost on me. If these are references to something else... the meaning is lost on me.

Edited by Paperstraw
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I prefer to run it up the middle with Estwing.

Which leads directly to that other thread: How many fossils have you destroyed....

At least three quarters of any large lottery I win will go directly to professional preparation of 30 years of back log of fossils in need of prep.

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If these are sports analogies, the meaning is lost on me. If these are references to something else... the meaning is lost on me.

"Estwing" in the post from Missourian is a reference to the hammer of choice of many chiselers of rock. Hammer and chisel is the frist step in matrix removal when acid doesn't know where to stop. Progressively less destructive devices are used after taking the big chunks off and you get closer to the fossil. Your piece looks like a hash plate. I usually keep these intact, maybe just exposing a little more of some shells. Then I go look for fossils completely free of matrix or with just a little cleaning necessary.

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Yeah.... sigh.....

Well, I'm kind of disappointed with this one, my geology professor said this was one of the nice pieces he'd seen, and those white shells (some sort of gastropod I assume) hd nice nodules all over the surface which have been dissolved.

Once the river's levels go down after the thaw I'm going to the opposite bank where I found this, I suspect there will have been significantly less foot traffic on that side, so might find some nice business.

Edited by Paperstraw
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Which leads directly to that other thread: How many fossils have you destroyed....

At least three quarters of any large lottery I win will go directly to professional preparation of 30 years of back log of fossils in need of prep.

AMEN!

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Yeah.... sigh.....

Well, I'm kind of disappointed with this one, my geology professor said this was one of the nice pieces he'd seen, and those white shells (some sort of gastropod I assume) hd nice nodules all over the surface which have been dissolved.

Do you mean nodes?

Good luck with the hunt.. if you're like me the fossil collecting/prepping learning curve is full of heartbreak, but the rewards keep you coming back to it.

Edited by Wrangellian
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No, they were like bumps, which is why I chose nodule or node as a descriptor.

Edited by Paperstraw
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There's always the "weathering bench." It's a slow boat, but it's a lot of fun sorting through the broken-down stuff. I'd think you could speed up the process a bit by bringing your specimins in and out of the cold weather.

I have not used either one of the following chemicals, but you might look into rewoquat and DMSO.

http://earth.boisest...aleontology.pdf

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Do you think Sonic Cleaner would be able to jossle the matrix free?

Yes, Sonic Cleaners are excellent for jossling fossils free of matrix. and teeth free of jaws... and echinoids free of the hassle of being one piece and being eble to spend eternity in a million pieces...

I have a sonic cleaner for sale... Cheap...

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You can also do the ol' acidize, clearcoat, acidize, clearcoat, acidize, clearcoat, etc. routine. It take time, but you will end up with excellent detail on the fossil.

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You can also do the ol' acidize, clearcoat, acidize, clearcoat, acidize, clearcoat, etc. routine. It take time, but you will end up with excellent detail on the fossil.

But how do you get the clear coat off :~()

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