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stromatolite?


brus

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Don't know...........layers are a bit far apart compared to what I normally find around here.

Brent Ashcraft

ashcraft, brent allen

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I'm curious - how often do stromatolites have crystalline banding like that? I've never seen one like that but I am very new at this. :P My first thought was that it's an agate, but while agates can be found near Lepoglava I'm not sure what sorts of characteristics they can have...

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Unless I'm looking at it wrong and those aren't crystals I'm seeing in there, which is somewhat likely.

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Do not know about the polished piece, but the large chunk looks like a banded agate to Me.

I do not see what I would expect from stromatolite.

Tony

Darwin said: " Man sprang from monkeys."

Will Rogers said: " Some of them didn't spring far enough."

 

My Fossil collection - My Mineral collection

My favorite thread on TFF.

 

 

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Stromatolite generally preserve in two ways. Carbonate (limestone/dolomite), which form by precipitation of the carbonate by localized pH changes caused by photosynthesis. The other way is when debris (sand) gets caught in the slime layer. These particles eventually fuse and form flint/chert.

My first thought when I saw your specimen was agate, but I am not a mineral guy. Agates are VERY similar to chert stromatolites.

Brent Ashcraft

ashcraft, brent allen

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Stromatolite generally preserve in two ways. Carbonate (limestone/dolomite), which form by precipitation of the carbonate by localized pH changes caused by photosynthesis. The other way is when debris (sand) gets caught in the slime layer. These particles eventually fuse and form flint/chert.

My first thought when I saw your specimen was agate, but I am not a mineral guy. Agates are VERY similar to chert stromatolites.

Brent Ashcraft

They can also be agatized, as what is found in the Yellowstone river.

Tony

Darwin said: " Man sprang from monkeys."

Will Rogers said: " Some of them didn't spring far enough."

 

My Fossil collection - My Mineral collection

My favorite thread on TFF.

 

 

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