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Identity HelpStrange rock?

27th Jan 2020 02:33 UTCburlene greene

Quite interesting any clues?

27th Jan 2020 02:36 UTCburlene greene

Once broken the inside

27th Jan 2020 04:10 UTCBob Harman

Where was it found?

Looks like it might be silicified limestone or a silicified  invertebrate fossil, like a shell. Your pix of the broken example shows the quartz replacement

Here in the sedimentary environment of South-central Indiana, I find silicified fossils (geodized fossils) quite often.    Quartz replaces the limestone or fossil, preferentially in cracks, enlarging them at points of weakness, hence the appearance.

Above is one Indiana shell example for reference. You can still see the shell fragments with quartz replacing the shell along point of weakness.    CHEERS.....BOB

27th Jan 2020 08:34 UTCV. Stingl

I think, Kyle had the right idea. No fossil.


28th Jan 2020 04:33 UTCburlene greene

I found it in Falmouth,Ma on the ocean shoreline thats really interesting because originally I thought fossil but when I broke into it which sadly wish I didn't but it appeared to be stone so as a beginner I had no idea it calcified into quartz.

27th Jan 2020 04:58 UTCKyle Beucke

To me, this looks like a breccia of rock fragments cemented by quartz with what vaguely appears to be comb texture.  The open space in the first photo could either be where a rock fragment broke or weathered out or remaining open space where deposition of quartz ceased.  


27th Jan 2020 13:27 UTCEd Clopton Expert

I agree with Kyle--looks like a quartz-cemented breccia with the breccia clasts partly weathered out.  Interesting rock.

28th Jan 2020 04:36 UTCburlene greene

Closer picture

28th Jan 2020 04:39 UTCburlene greene

Different angle 

28th Jan 2020 18:19 UTCDon Saathoff Expert

Hello Burlene,
There are obviously a couple of things going on here.  Try, with a pocket knife, to scratch the material in the hollows and the material between the hollows and let us know the result.

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