fosceal2 Posted January 24, 2008 Share Posted January 24, 2008 My brother in law calls this stuff chert , they use it like gravel when it is small. I have not been able to locate a source as when I see it it is in a creek or has slid down the mountain side to a road. The whiter the background the more chalk like it feels, the greyer stuff is denser and more quartz like in feel. Out of the hundreds of lbs I have collected Only three had fossils ( clear shell imprints, one with an actual shell). The whiter ones grow lichens or algae like limestone. I wonder is this Banded iron Formation rock like Dr.Bruce Stinchcomb describes in his Worlds oldest fossils book? I have more pictures at photobucket under FOSCEAL album chert. The graining looks woodlike but this is not wood. Any thoughts appreciated. Cecelia Link to comment Share on other sites More sharing options...
jkfoam Posted January 24, 2008 Share Posted January 24, 2008 Cecelia, If I had found that rock I would call it Chert or Flint. We find chert or flint nodules imbedded in limestone frequently here in central texas but none is as colorful as the piece you have. Ours are generally brown and tan, some with banding. The age of the piece would be equivalent to the host rock that contained the nodule. JKFoam The Eocene is my favorite Link to comment Share on other sites More sharing options...
worthy 55 Posted January 24, 2008 Share Posted January 24, 2008 Could it be petrified wood ?? Cool looking anyways! It's my bone!!! Link to comment Share on other sites More sharing options...
fosceal2 Posted January 24, 2008 Author Share Posted January 24, 2008 Here is why I do not believe it is wood. I have found this shell and one other plus some snail? Limpit looking impressions. It does have a grain look though and I do wonder is it caused by algae growth or is it just mineral. Thank you to gentleman from TX. I am from Virginia Beach, VA. We had grey sand, grey clay, and grey concrete. I am still learning the basic rock names. The colors of this Chert are just fascinating to me. Imbedded in Limestone? Hmmm like pockets of it? Same age as host rock. Cool OK now as soon as it warms up enough for me I am going to WV and see if I can find some -like a seam -in situ .So if I do and it is in fossil limestone that can be dated by common fossils then I will have backed into age of this rock- Correct? Cecelia Link to comment Share on other sites More sharing options...
Gatorman Posted January 24, 2008 Share Posted January 24, 2008 wow thats some pretty stuff Link to comment Share on other sites More sharing options...
Guest solius symbiosus Posted January 24, 2008 Share Posted January 24, 2008 Google "mohs scale of hardness". If it is chert, it should be about 7. The dark and light bands are probably the same material. If they weren't, one would see differential rates of weathering. Link to comment Share on other sites More sharing options...
tomclark Posted January 25, 2008 Share Posted January 25, 2008 Looks more like nice quality Agate than average chert although I believe geologically they are the same thing. agate chert, jasper,etc. Agatized shells or fossiliZed in that way are often found, in sedimentary layers within limerock and other types of sedimentary deposits, often with clay layers above and below them. Link to comment Share on other sites More sharing options...
Guest solius symbiosus Posted January 25, 2008 Share Posted January 25, 2008 Looks more like nice quality Agate than average chert although I believe geologically they are the same thing. agate chert, jasper,etc. Agatized shells or fossiliZed in that way are often found, in sedimentary layers within limerock and other types of sedimentary deposits, often with clay layers above and below them. I use chert as a catch all term for all the variations of chalcedony. Link to comment Share on other sites More sharing options...
Ted Posted January 27, 2008 Share Posted January 27, 2008 That is beautiful chert , I would look for the layering to be sponge . The shell fossil would be unlikely to be with banded iron stromatolite . Link to comment Share on other sites More sharing options...
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