winnph Posted April 4, 2019 Share Posted April 4, 2019 (edited) Found this on the beach the other day along Puget Sound north of Seattle, and I just polished one face a bit (first photo) with some sandpaper to see the un-weathered stone. Is this siltstone, petrified wood, something else? Has anyone seen one with iron like this? Edit: I sanded it some more and took another photo. Pretty sure this is wood, based on the grain, but I'm no expert! Edited April 4, 2019 by winnph Added photo Link to comment Share on other sites More sharing options...
Bronzviking Posted April 5, 2019 Share Posted April 5, 2019 I'm not seeing petrified wood. Its a sedimentary rock containing iron-ore which is the rust stained section. It could be banded sandstone or siltstone typical of the the layered pattern or striations you have exposed. Link to comment Share on other sites More sharing options...
ynot Posted April 5, 2019 Share Posted April 5, 2019 Agree with sandstone with iron concretions. 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. Link to comment Share on other sites More sharing options...
winnph Posted April 5, 2019 Author Share Posted April 5, 2019 This vertical grain within the horizontal banding where it's been sanded down is what looked more like wood to me. Link to comment Share on other sites More sharing options...
ynot Posted April 5, 2019 Share Posted April 5, 2019 I have never seen wood that looks like that, but it is strange for a sandstone or siltstone also. 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. Link to comment Share on other sites More sharing options...
DPS Ammonite Posted April 5, 2019 Share Posted April 5, 2019 Do not discount wood. When I see such regular bands with no visible sand or silt grains I think: could this be wood? Microscopic photos might be revealing. What is very interesting is the chevron folding of the laminations. I have seen this in petrified wood before. In the picture below, pressure from the top and bottom of the photo (yellow arrows) created chevron folds. Along the axis of the folds you can see white lines (red arrow). Note the reddish brown folded layer (close to the yellow arrows) on the left side of photo that probably was straight to curving before being distorted. This could be a severely contorted piece on non wood. The evenness and length of the laminations make me lean towards a piece of crushed petrified wood. See my piece of petrified wood with chevron folds from Northern California: 3 My goal is to leave no stone or fossil unturned. See my Arizona Paleontology Guide link The best single resource for Arizona paleontology anywhere. Link to comment Share on other sites More sharing options...
Al Tahan Posted April 5, 2019 Share Posted April 5, 2019 3 hours ago, winnph said: This photo (plus polished section) makes me lean towards wood remains. There seems to be a “fiber looking” texture. I’ve seen a good amount of concretions and iron staining in my field experiences. This doesn’t seem to like up that well. I would have expected a much smoother less fibrous/ detailed texture. The polished cross section also shows a good amount of texture and detail to be geologic. The host rock does not appear to be concretionary either. Just my 2 cents 1 Link to comment Share on other sites More sharing options...
winnph Posted April 5, 2019 Author Share Posted April 5, 2019 (edited) I just tested the iron looking sections with a powerful magnet and it is not at all magnetic. That was a surprise... It's very metallic and shiny when polished (shown at an angle to the light in the first photo here), and obviously rusty-looking when not polished. The second photo (added via edit) shows it as close as I can get with my phone camera under bright LED lighting. Wish I could take microscopic photos, too! Edited April 5, 2019 by winnph Added second photo Link to comment Share on other sites More sharing options...
ynot Posted April 5, 2019 Share Posted April 5, 2019 1 hour ago, winnph said: I just tested the iron looking sections with a powerful magnet and it is not at all magnetic. Most iron minerals are not magnetic. 2 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. Link to comment Share on other sites More sharing options...
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