yzhang Posted March 22, 2014 Share Posted March 22, 2014 (edited) Hello all, I got a piece of marine reptile fossil from UK this spring break. It supposed to be a pliosaur jaw fragment from Krimmeridge clay (upper Jurassic), Portland Dorset, UK. There are some little pieces of crystal embedded in the bone, see photos attached. I knew crystallization is common for fossilized wood, but is this normal for bones? Or are those crystals embedded into the bone artificially? Though I can not see a reason why someone want to do that... Thank you! little pieces of crystals: Edited March 22, 2014 by yzhang Link to comment Share on other sites More sharing options...
yzhang Posted March 22, 2014 Author Share Posted March 22, 2014 two big tooth-sockets: and a small tooth for replacement: Link to comment Share on other sites More sharing options...
yzhang Posted March 22, 2014 Author Share Posted March 22, 2014 Link to comment Share on other sites More sharing options...
Mediospirifer Posted March 22, 2014 Share Posted March 22, 2014 (edited) Quartz varieties are fairly common in a lot of rock types. These include crystalline quartz, agate, and chalcedony. I suspect that's what you're seeing here. Calcite will also form crystals in voids (like the interior spaces of fossils), and is common in carbonate-bearing rocks, especially limestone. You can tell calcite from quartz by immersing it in a weak acid (like vinegar): calcite will effervesce (give off air bubbles), quartz won't. Just be aware that the bubbling (if it happens) is your rock slowly dissolving. A few hours probably won't change it that you can see, but you shouldn't repeat the experiment too many times. The vinegar bath won't hurt quartz. There are other minerals that can infill fossils, but those two are the most common that I know of. Nice piece! Edited March 22, 2014 by Mediospirifer 1 Link to comment Share on other sites More sharing options...
Taogan Posted March 22, 2014 Share Posted March 22, 2014 It's all natural, bones have small voids which fill with various minerals on fossilisation, nothing wrong with this piece. 1 Link to comment Share on other sites More sharing options...
DE&i Posted March 22, 2014 Share Posted March 22, 2014 That's a fine piece..I've similar finds from the Lower Oxford Clay here. http://www.thefossilforum.com/index.php?/gallery/image/26535-fragmented-girdle-bone-2/ Regards, Darren. 1 Regards.....D&E&i The only certainty with fossil hunting is the uncertainty. https://lnk.bio/Darren.Withers Link to comment Share on other sites More sharing options...
yzhang Posted March 22, 2014 Author Share Posted March 22, 2014 Quartz varieties are fairly common in a lot of rock types. These include crystalline quartz, agate, and chalcedony. I suspect that's what you're seeing here. Calcite will also form crystals in voids (like the interior spaces of fossils), and is common in carbonate-bearing rocks, especially limestone. You can tell calcite from quartz by immersing it in a weak acid (like vinegar): calcite will effervesce (give off air bubbles), quartz won't. Just be aware that the bubbling (if it happens) is your rock slowly dissolving. A few hours probably won't change it that you can see, but you shouldn't repeat the experiment too many times. The vinegar bath won't hurt quartz. There are other minerals that can infill fossils, but those two are the most common that I know of. Nice piece! Mediospirifer: Thanks! I'll do the test and find out whether they are quartz or calcite. -- Yzhang Link to comment Share on other sites More sharing options...
yzhang Posted March 22, 2014 Author Share Posted March 22, 2014 It's all natural, bones have small voids which fill with various minerals on fossilisation, nothing wrong with this piece. Taogan: Thanks! This makes a lot of sense as I also find little holes yet to be filled by minerals on that piece :-) That's a fine piece..I've similar finds from the Lower Oxford Clay here. http://www.thefossilforum.com/index.php?/gallery/image/26535-fragmented-girdle-bone-2/ Regards, Darren. Darren: Thank you, the plesiosaurus bone you found looks great! Link to comment Share on other sites More sharing options...
Natascha Posted March 24, 2014 Share Posted March 24, 2014 yeah, I have some nimravid bones where you can see the inside where the marrow used to be, and it's now filled with crystals. Pretty awesome, isn't it Link to comment Share on other sites More sharing options...
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