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I can not find a similar image or info on the net to identify my presumably Cave stalagmite. I would like to know where and how it formed. Now the black interfiling i'm assuming to be water that fossilized somehow inside the after seeping through layers of rock until it got trapped in this reservoir of stalagmite, It is almost crystal structured meaning no pockets of air or any other substances so it must of been filtered through sand and coal to get the black color.

This is all thought theory based and I have no knowledge on stalagmite or how they formed thus being my first sample. Please correct me if I am wrong.

If my theory is correct on the black filling being water does anyone know how this process occurred and what is it composed of?

Also any information or photos that resemble this specimen would be of great help.

enter image description here

enter image description here

enter image description here

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closed as off-topic by Jan Doggen, user12525, trond hansen, Semidiurnal Simon, BillDOe Aug 29 at 20:13

This question appears to be off-topic. The users who voted to close gave this specific reason:

  • "Questions about rock identification requests are off-topic. For more information, see the announcement on meta." – Jan Doggen, Community, trond hansen, Semidiurnal Simon, BillDOe
If this question can be reworded to fit the rules in the help center, please edit the question.

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    $\begingroup$ What makes you think it is petrified wood? It superficially looks very much like a flint/chert nodule.silysavg.com/flintknapping/images/… $\endgroup$ – Siv Nov 26 '15 at 17:18
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    $\begingroup$ Does the pale material react with acid? does the dark "watery" interior scratch glass? $\endgroup$ – Siv Nov 26 '15 at 17:24
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    $\begingroup$ By the way, petrified wood IS chert (mostly). This is why it's petrified. $\endgroup$ – Gimelist Nov 27 '15 at 3:02
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    $\begingroup$ Make a better picture. You want us to look at the dark center and then your photograph uses backlighting which makes looking at the front actually more difficult! $\endgroup$ – Jan Doggen Nov 27 '15 at 8:28
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    $\begingroup$ No progress on this one unless we have a really well illuminated close up, both of the black core and the pale crust, including the nature of the contact. Also useful to know where it originally came from. $\endgroup$ – Gordon Stanger Nov 27 '15 at 20:39
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This is chert. It doesn't appear to be as opaque as the flint pictured at the link below, but I am color blind and usually wrong when it comes to color. https://en.wikipedia.org/wiki/Chert#/media/File:Flint_with_weathered_crust.JPG

Your theory is incorrect. Chert is amorphous, has no crystalline structure, which is what I see. To better tell if it is petrified wood as was suggested in the comments, picture 2 needs to be retaken.

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