Mofraqi Posted July 30, 2010 Share Posted July 30, 2010 Hi everyone I'm new to the whole fossil scene and had a few questions. I'm actually in to lapidary, rock tumbling, and handmade Jewelry. Anyways I have been polishing rocks I found in a riverbed and noticed a lot of them are loaded with fossils, now the rock I'm tumbling and making cabs out of is called Chert/Flint and even Jasper my question is I read those rocks are Precambrian era rocks and are roughly 500 million to 3.5 billion years old, does this mean the fossils are that old as well? I feel so stupid that I never noticed all the little animals and bugs all over them. The rocks are very waxy feeling and smooth with colors like white and grey and some browns and yellows and a lot are transparent (quartz type). Does anyone know about these??? Link to comment Share on other sites More sharing options...
siteseer Posted July 30, 2010 Share Posted July 30, 2010 Yes, fossils are as old as the rock layer in which are found (older than the layer above; younger than the layer beneath). However, visible fossils are very rare in Precambrian rocks. Random shapes and indentations in rocks can resemble animals but lack the diagnostic structures of even the comparatively simple forms that were alive during that time. Chert, flint, and jasper are minerals. I don't think you can find fossils within them. Rarely, insects have been found within selenite crystals but they may be mere thousands of years old. ...now the rock I'm tumbling and making cabs out of is called Chert/Flint and even Jasper my question is I read those rocks are Precambrian era rocks and are roughly 500 million to 3.5 billion years old, does this mean the fossils are that old as well? I feel so stupid that I never noticed all the little animals and bugs all over them. Does anyone know about these??? Link to comment Share on other sites More sharing options...
Mofraqi Posted July 30, 2010 Author Share Posted July 30, 2010 Yes, fossils are as old as the rock layer in which are found (older than the layer above; younger than the layer beneath). However, visible fossils are very rare in Precambrian rocks. Random shapes and indentations in rocks can resemble animals but lack the diagnostic structures of even the comparatively simple forms that were alive during that time. Chert, flint, and jasper are minerals. I don't think you can find fossils within them. Rarely, insects have been found within selenite crystals but they may be mere thousands of years old. Can I post pics because I believe these are at least devonian period fossils I can clearly Identify some. I also have some that look like trilobites but slightly different also some weird donut shapped ones like an O with a dot in the middle. some Crinoids are very visible which are cambrian and some after. I maybe be totally off to. What else could those rocks be?? They look identical to the Chert in wikipedia. Grey whiteish waxy feeling some browns? Where I live use to be a sea. Link to comment Share on other sites More sharing options...
Mofraqi Posted July 30, 2010 Author Share Posted July 30, 2010 Wikipedia said this----- Chert and Precambrian fossils===The cryptocrystalline nature of chert, combined with its above average ability to resist weathering, recrystallisation and metamorphism has made it an ideal rock for preservation of early life forms. Link to comment Share on other sites More sharing options...
MOROPUS Posted July 30, 2010 Share Posted July 30, 2010 Yes, fossils are as old as the rock layer in which are found (older than the layer above; younger than the layer beneath). However, visible fossils are very rare in Precambrian rocks. Random shapes and indentations in rocks can resemble animals but lack the diagnostic structures of even the comparatively simple forms that were alive during that time. Chert, flint, and jasper are minerals. I don't think you can find fossils within them. Rarely, insects have been found within selenite crystals but they may be mere thousands of years old. Sorry to tell this, but chert or flint are both minerals that can held fossils, even replacing the original forms. Chert facts Flint facts Most of the chert/flint strata I know, was deposited on marine or shallow water on late Paleozoic, Mesozoic or early Caenozoic eras, and have fossils. If there is a lot of fossils near the flint/chert layers, they will be, 90%, post-Precambrian. This is an example of flint encased echinoid (Cretaceous Cidaris from England) And some Paleozoic crinoid stems from England aswell in chert: Link to comment Share on other sites More sharing options...
Mofraqi Posted July 30, 2010 Author Share Posted July 30, 2010 I have both of those found in those pictures, siteseer was talking about selenite crystals but these are not, they are quartz crystal! Selenite crystals have a hardness of 2 on the mohs scale so I could see them not being to old but quartz has a 7-7.5 rating on that same scale, only 3 below diamond. I know this because I tumble rocks and it takes a week or better to shape these rocks with 80 grit carbon steel which has a hardness of 9.5. Anyways I will try to post some pics and you guys could tell me what you think. Link to comment Share on other sites More sharing options...
pleecan Posted July 30, 2010 Share Posted July 30, 2010 Chert, flint, and jasper are minerals. I don't think you can find fossils within them. Sorry but I do not agree... Chert can contain fossils. see thread: http://www.thefossilforum.com/index.php/topic/13402-devonian-fossil-in-chert-matrix-bois-blanc-formation-fort-erie-on-canada/page__p__150979__hl__%2Bbois+%2Bblanc__fromsearch__1#entry150979 PL Link to comment Share on other sites More sharing options...
MOROPUS Posted July 30, 2010 Share Posted July 30, 2010 I agree with Pleecan. I have found nice Mesozoic briozoans in English silex (chert or flint),and some sponges are found inside chert nodules. Look at this echie spine I found in the internet: Link to comment Share on other sites More sharing options...
Mofraqi Posted July 30, 2010 Author Share Posted July 30, 2010 Well here it goes!!!!! Sorry some are fuzzy but my camera is not made for close ups like that, I did my best! Link to comment Share on other sites More sharing options...
Auspex Posted July 30, 2010 Share Posted July 30, 2010 Most of what I can easily make out are pieces of crinoid stems. These would not be precambrian. "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...
tracer Posted July 30, 2010 Share Posted July 30, 2010 not only can chert contain fossils, but fossils can be completely pseudomorphed in chert. and it doesn't take anywhere near half a billion years for it to happen. chert fossils are cut and polished all the time in the form of "petrified wood". and i've got a great little red jasper piece that i polished to display the white fenestrate bryozoan fossil integrated into it. 1 Link to comment Share on other sites More sharing options...
Mofraqi Posted July 30, 2010 Author Share Posted July 30, 2010 (edited) Most of what I can easily make out are pieces of crinoid stems. These would not be precambrian. So these are Cambrian not precambrian right? 250 million years old maybe? Edited July 30, 2010 by Mofraqi Link to comment Share on other sites More sharing options...
tracer Posted July 30, 2010 Share Posted July 30, 2010 ordovician to recent. NOT cambrian link Link to comment Share on other sites More sharing options...
Mofraqi Posted July 30, 2010 Author Share Posted July 30, 2010 (edited) ordovician to recent. NOT cambrian link 443 million to 480 million and newer! I don't know what to do with all these i have over 100 pounds of them! Edited July 30, 2010 by Mofraqi Link to comment Share on other sites More sharing options...
MOROPUS Posted July 30, 2010 Share Posted July 30, 2010 you can send them to someone who will appreciate that Paleozoic stuff! Link to comment Share on other sites More sharing options...
Mofraqi Posted July 30, 2010 Author Share Posted July 30, 2010 you can send them to someone who will appreciate that Paleozoic stuff! Maybe some trades are in order! Link to comment Share on other sites More sharing options...
Auspex Posted July 30, 2010 Share Posted July 30, 2010 I don't know what to do with all these i have over 100 pounds of them! Design a bunch of fossil jewelry 1 "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...
Mofraqi Posted July 30, 2010 Author Share Posted July 30, 2010 Design a bunch of fossil jewelry I have enough rocks fossils and minerals to last till the next extinction! You name it I got it! Ammonites fall out of my closets. I just sold a really nice piece of Fluorite to the Smithsonian Magazine for photos! Maybe I could call the Jewelry "Jurassic Bling" Link to comment Share on other sites More sharing options...
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