Looking For Suggestions What These Nodules Are Made Of To Look For Macros

[DE&i]

Hi everyone,

I have some nodules here that Aidie_Uk and I would like to break down and search for macro-fossils but we are struggling to establish what they are made out of. They are from the Isle of Wight and are:

Aptian 111-121 MYA / Early Aptian / Atherfield Clay / from the perna beds.
I can clearly see Lepidotes teeth in there I’m sure there will be a lot of other types of teeth as well.

Regards,

Darren.

[painshill]

Hi Darren

I'm not so sure those are "nodules" as most people would understand them. Are you getting them out of the cliffs like that or finding them as chunks on the beach (Atherfield Point maybe?). If the latter, they're more likely to be broken blocks of very coarse silicified sandstone which will be a real pain to break down - except physically and painstakingly. That material was formed in turbulent conditions and will indeed be full of fossil marine detritus but it's also pretty hard stuff.

[DE&i]

Hi Roger,

Thank you for looking at these Aidie_Uk informs me they where found normally only exposed in the winter at yaverland but lumps can sometimes be found on the shore.

They certainly feel like they would be a tough cookie to crack perhaps not worth the time and effort which is a shame as they look as though they have a lot to offer.

Regards,

Daren.

[Auspex]

Maybe something like boiling them in a Trisodium Phosphate solution could soften things up? A little experimentation could be worth the effort!

[Adie_uk]

I think hydrofluoric acid can break down the silica (it can dissolve/break down glass) just having a look to see if its something you can buy? but may well dissolve the teeth too?

Any chemists on TFF?

may well be worth just putting in a bag and putting in a vice and crush with even pressure, I know its basic but maybe the quickest and most cost effective?

boiling some now will see if much falls apart or even better if it softens it but wont hold my breath, may then try the freezer over night then boiling water again in the morning, in the mean time will try crushing.

Edited August 31, 2013 by Adie_uk

[Adie_uk]

found a few bits, would have more but my daughter knocked my pot on the floor, DULP!!! Found some of them the others are destine for the hoover.

mainly few bits of bone , verts and teeth. I think also lots of coprolites?

Edited August 31, 2013 by Adie_uk

[painshill]

Hydrofluoric acid most certainly will dissolve silica and silicates. It’s the acid of choice for solubilizing rock samples prior to chemical analysis because it also dissolves most oxides and a bunch of other things too.

At professional levels it is also used for dissolving silicate rocks to extract organic fossils but if the fossils are silica-replaced it will attack those as well. Often, cellulose nitrate dissolved in amyl acetate is applied first to create a film around the organic areas that allows the surrounding rock to be dissolved without damage to the fossils.

But it’s nasty stuff. As well as being extremely corrosive to the skin, it’s a highly toxic contact poison that’s absorbed through the skin and even small exposures can result in a heart attack. More dangerous still because skin burns are initially painless such that accidental splash exposures may go un-noticed for some time.

It’s not readily available except from specialist chemical suppliers. There are no household products containing it at concentrations high enough to be effective for dissolving rocks, but it is sometimes a low-level component of things like proprietary rust-removal products.

All in all, I’d say it’s a bad idea to have this stuff kicking around your home.

I am a (bio)chemist.

[Adie_uk]

yep I think that's a big no no, looks very nasty and quite dangerous. I suck with the highly scientific and specialist technique of a lump hammer lol I know its not ideal and may have damaged some fossils but I think where they are so many will survive.

Darren just smash it up and sieve it! "old school" you should find far more than me

[Auspex]

DO NOT mess with hydroflouric acid!

[Ludwigia]

DO NOT mess with hydroflouric acid!

I'll also underline that.

[Herb]

I would not mess with ANY acids at home except dilute muriatic or acetic.

Its a bear to break down material like you have, Mechanical breaking and hope for the best. Boiling in a TSP solution. Alternating freeze/thaw cycles. Ultrasonic cleaner. Not sure bits of bone and teeth would be worth the effort.