Petrified Posted July 23, 2011 Share Posted July 23, 2011 (edited) Ive been reading up on stigmaria roots and it says they are all sandstone cast. Im actually finding them agate cast. On a hardness scale from 1-10 diamond being hardest these stigs Im finding are around 7 1/2. Now I did find a few sandstone cast also. How are the majority of them Im finding agate cast when its not known in PA to have agate cast fossils that Im aware of? Not that Im complaining because they are polishable due to the hardness. I had one cut today and polished and agate couldnt even scratch it. We were rubbing agate on the suface of the cut piece and it didnt even make a mark. For example if you rub a diamond on an agate it would scratch it. Then we tested it on a piece of petried wood from oregon (agate) and it scratched the petrified wood from oregon and didnt affect the stig at all. The weight of these fossils that Im finding are extremely heavy compared to the sandstone cast ones. They also have a reddish brown color whereas the sandstone ones have a grey or black color. All in all we both were amazed on how hard the fossils were. Edited July 23, 2011 by Petrified Definition of a fossil= Love at first site. Link to comment Share on other sites More sharing options...
flyguy784 Posted July 23, 2011 Share Posted July 23, 2011 (edited) Very interesting indeed. I've found stigmaria and you're right, it's always a quite soft material. Let's see what the experts say. Are you sure of the age? You should verify the formation as well. I'm sure that'll be important for a valid response. Edited July 23, 2011 by flyguy784 Link to comment Share on other sites More sharing options...
Terry Dactyll Posted July 23, 2011 Share Posted July 23, 2011 It sounds very interesting... Unusual preservation sometimes means its possible that plant cell structure has preserved... It will be interesting to se a micro photo of the polished root... Cheers Steve... And Welcome if your a New Member... Link to comment Share on other sites More sharing options...
Auspex Posted July 23, 2011 Share Posted July 23, 2011 ...It will be interesting to see a micro photo of the polished root... Yes; there is potential for this to be quite extraordinary! "There has been an alarming increase in the number of things I know nothing about." - Ashleigh Ellwood Brilliant “Try to learn something about everything and everything about something.” - Thomas Henry Huxley >Paleontology is an evolving science. >May your wonders never cease! Link to comment Share on other sites More sharing options...
Petrified Posted July 23, 2011 Author Share Posted July 23, 2011 Heres a piece of stimaria root that I had cut and polished. When I look closely to the object it gives a little glitter from the crystals in it. When you try and polish sandstone it will burn on the attempt of polishing it. The sandstone material will not get smooth at all. This root was very easy to polish and its smooth like glass. What else is unusual about the pieces that preserved are the weight of them. I have some sandstone cast ones that are really light compared to the agate formed stigs. Compared to weight differences I would say a same size piece would weight about 3-4 times heavier. Now what I want to know is since these are only roots Im finding wheres the Lepidodendron part of the trees. It would be sweet if the Lep parts have the same preservation. Im going to look around to see if any lep parts pop up anywhere. It would be nice to have a huge piece cut and polished. So Im just hoping that a tree fell somewhere and got preserved real nice. Heres a few pics of the cut piece. Now in the future I will find some stigs much better and more colors than this pattern. This cut was more to see if there was anything to be seen in the inside of the stig. Definition of a fossil= Love at first site. Link to comment Share on other sites More sharing options...
Auspex Posted July 23, 2011 Share Posted July 23, 2011 I think the agatization occurred after the cast was formed; a pseudomorph, if you will, since there is no sign of an organized vascular structure. It's quite wonderful! "There has been an alarming increase in the number of things I know nothing about." - Ashleigh Ellwood Brilliant “Try to learn something about everything and everything about something.” - Thomas Henry Huxley >Paleontology is an evolving science. >May your wonders never cease! Link to comment Share on other sites More sharing options...
Plantguy Posted July 23, 2011 Share Posted July 23, 2011 Petrified, yep, most of what I've seen are shale/siltstone/sandstone casts also...Its gonna be interesting to see if the polished slices show any internal structures. Seems there would have had to been the necessary silica rich sources available for replacement before the cell structures started to break down to capture that sort of detail. Local geologic processes are/can be very unique. Even if they dont show significant details internally its still neat to have something a little bit different! Keep us posted. Regards, Chris Link to comment Share on other sites More sharing options...
Plantguy Posted July 23, 2011 Share Posted July 23, 2011 Petrified, yep, most of what I've seen are shale/siltstone/sandstone casts also...Its gonna be interesting to see if the polished slices show any internal structures. Seems there would have had to been the necessary silica rich sources available for replacement before the cell structures started to break down to capture that sort of detail. Local geologic processes are/can be very unique. Even if they dont show significant details internally its still neat to have something a little bit different! Keep us posted. Regards, Chris Went out to work on my son's car and started to post and just came back...looks like we got pictures already....cool! Regards, Chris Link to comment Share on other sites More sharing options...
Petrified Posted July 26, 2011 Author Share Posted July 26, 2011 Me and my friend just cleaned up the spot real good. We picked a few pieces are agatized. Hes going to go through them and polish them to show the patterns inside the roots. He showed me a few examples today its looking promising. We are going to cut up a bunch of pieces to see what one has the best details. I gave hime a agatized log earlier today for him to have. Its competely round and I cant imagine the details it would show on the wood. Well post the best ones when were done. Definition of a fossil= Love at first site. Link to comment Share on other sites More sharing options...
Terry Dactyll Posted July 28, 2011 Share Posted July 28, 2011 (edited) Certianly worth a try... Preservation of the vascular structure isnt that common...Looks nice... Edit... I found the photos of the vascular structure preserved in a pice of stigmaria collected at a friends hunting ground... we polished a bit up to see if we could see the cell structure... Edited July 28, 2011 by Terry Dactyll Cheers Steve... And Welcome if your a New Member... Link to comment Share on other sites More sharing options...
TqB Posted July 28, 2011 Share Posted July 28, 2011 Steve - that's fantastic preservation; does it look "normal" on the outside surface? Tarquin Link to comment Share on other sites More sharing options...
Terry Dactyll Posted July 28, 2011 Share Posted July 28, 2011 Tarquin... Yep... its normal on the outside but in plan something was obviously different and we couldnt wait to section a piece... Its from Neils opencast... Pretty special hey Heres the elevation of the above spcimen... Cheers Steve... And Welcome if your a New Member... Link to comment Share on other sites More sharing options...
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