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Mykkhul97

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Mykkhul97

I have a 1/4" slab of ?  I have no clue what it is. It looks like jasper or agate? It is solid considering how thin it is. 

20181218_200533.jpg

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Herb

maybe banded agate

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abyssunder
20 minutes ago, Mykkhul97 said:

Common?

Not so common. :)

 

5c1af28792880_Jaspilite_banded_iron_formation_(Soudan_Iron-Formation_Neoarchean_2.69_Ga_Stuntz_Bay_R-und_State_Park_Soudan_Minnesota_USA)_10_(19228731171).thumb.jpg.e00d3d0924eb6307f734c2c0097b3cc0.jpg

 

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Al Tahan
24 minutes ago, abyssunder said:

Not so common. :)

 

5c1af28792880_Jaspilite_banded_iron_formation_(Soudan_Iron-Formation_Neoarchean_2.69_Ga_Stuntz_Bay_R-und_State_Park_Soudan_Minnesota_USA)_10_(19228731171).thumb.jpg.e00d3d0924eb6307f734c2c0097b3cc0.jpg

 

Kinda does seem like @abyssunder is on the right track. +1 for jaspillite

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supertramp
LordTrilobite

That's quite pretty.

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UtahFossilHunter
3 hours ago, supertramp said:

or alternatively a slab of a migmatitic rock (with ptygmatic folding)

ciao

The colors in the top image (while not conclusive evidence) indicate agate or Jaspillite rather than migmatite. Notice in your links all of the migmatite samples have dark bands with either pink or white layers intermingled. The lights and darks in migmatite is due to vigorous metamorphism. Pressure and heat induce foliation in igneous minerals and heat some to the point of nearly melting (or actually melting in some minerals on the lower end of Bowen’s reaction series). Pinks are usually potassium feldspars in migmatite. Darks typically being amphiboles. Agate can be any color depending on the trace elements inside it. Jaspillite is moderately metamorphosed alternating bands of hematite and silica like in banded iron formations where iron is creating the extravagant coloring. If @Mykkhul97 so desired, testing the Moh’s hardness and streak of several of the bands to determine whether the whole piece is silica as it is in typical agate, alternating bands of hematite and other iron rich minerals and silica in Jaspillite, or several different high-heat igneous minerals like in migmatite would help rule out a couple of them.

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Mykkhul97

Well I came across a tub filled with slabs of everything and I only know a handful of them. So here is a few more pics if you or anyone could help me. Thank you very much! 

20181223_132818.jpg

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abyssunder

I see features of agate.

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