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What's covering my plesiosaur vertebra? How to clean


pachy-pleuro-whatnot-odon

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An easier and less risky option may be to keep the specimen in an airtight container with a desiccant.

 

That iron and that sulfur love to absorb moisture. Temperature is not really a concern if mine keeps the humidity low!

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12 hours ago, LabRatKing said:

Distill it!

 

or try a high proof grain drinking alcohol! Over here we have “Everclear” which most labs keep on hand for tricky reactions.

 

we use the MEK/ Methanol denatured in the labs daily. To date it has not interfered with any reactions.

only exception is what we use in the HPLC, but that’s not an issue here.

 

:BigSmile:

 

Unfortunately, I don't really have any working space or tools to do things like distilling my own alcohol. Even for air scribe work I'm stuck with a Dremel engraver, or going to somebody who'll let me use their tools, for now. Also, food-grade alcohol, such as "Everclear", doesn't seem to be as accessible here. In fact, in France you can only buy it if you're a company holding a special permit. I have found some wine spirits in abroad, including a brand called "Navimar", but almost nobody seems to sell across the border. And when they do, prices are between €30-45, making 5 litres quite an investment.

 

12 hours ago, LabRatKing said:

An easier and less risky option may be to keep the specimen in an airtight container with a desiccant.

 

That iron and that sulfur love to absorb moisture. Temperature is not really a concern if mine keeps the humidity low!

 

And while I've thought of keeping the specimen that way, this, for me, would defeat the purpose of owning the specimen. Not to mention I would always feel unsafe about it causing an outbreak of pyrite disease.

'There's nothing like millions of years of really frustrating trial and error to give a species moral fibre and, in some cases, backbone' -- Terry Pratchett

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Good news, though! Today I received the pyrite-stabilizer, including its instructions, as per below:

Quote

Use of Pyrite-Stabilizer


In general:
The Pyrite-Stabilizer (based on Monoethanolamine Thioglycolate) will be used for neutralization of sulphuric acid resulting from exfoliation/decay of pyrite-bearing fossils. With this Pyrite-Stabilizer a further exfoliation/decay can be stopped.

Handling:

  1. Clean the fossil mechanically with a brush (do not use water in this step!). The specimen must be completely dried out.
  2. Now the sample will be placed in solution of about 97% alcohol (e.g., grain alcohol) and 3% of Pyrite-Stabilizer.
    (The fossil should be completely covered by the solution. For this purpose basins made of glass are the best. The object to be cleaned should, if possible, not touch the sides of the container).

    During the chemical reaction the decayed pyrite will be neutralized. Depending on the degree of decay the solution will be tint violet to black. In general the sample should not be placed in the solution for more than 4 hours (duration depends on colour: the brighter the solution, the longer can be the retention time).
  3. Afterwards the fossil should be cleaned with (pure) alcohol (do not use water!).
  4. Repeat step 2 and 3 until the solution remains clear or attains only a slightly pink tone - the pyrite is now stabilized. For every round use fresh solution.
  5. At the end the sample should be placed in pure alcohol overnight (12 hours), so that the last decay components can be eliminated.
  6. After air-drying, the fossil is protected and can re-enter the collection.

Note:
For storage please use a dry place. Otherwise the pyrite will restart to oxidize. You can use small packages of silica gel to protect the fossils (this gel is able to absorb the humidity).

 

1491502861_datasheetforpyrite-stabilizer.thumb.jpg.a2256271c350201a51b6a17265895633.jpg

 

While the English text refers to using grain alcohol - i.e., food-grade - the German text refers to "Spiritus" (it's a German product, so I take this as significant rather than an error in translation). From personal communication with the seller, I've been informed that burning alcohol or, indeed, ethanol with MEK and benzoate denatorium works perfectly well in combination with the pyrite-stabilizer. As such, I'll probably go for this option.

 

The downside, however, seems to be that the effects of this treatment, much like that of any other pyrite-treatment, does not appear conclusive, and the piece remains a risk to the rest of my collection. As such, it seems that I'll need to follow these steps after all:

On 2/17/2021 at 3:29 PM, Ptychodus04 said:

6. Dry in oven on low heat for several hours.

7. Procure some Paraloid B72 and mix 1 part plastic with 50 parts acetone.

8. Submerge specimen in solution until bubbles stop coming out.

9. Allow to dry on a cardboard flat in a well ventilated area.

 

This leaves me with another question: what do I do with the left-over Paraloid that I've used to seal the specimen in? Should I now consider this contaminated and get rid of it, can it safely be re-used, or should I only re-use it for other pyrite-cases? Any advise, @Ptychodus04?

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'There's nothing like millions of years of really frustrating trial and error to give a species moral fibre and, in some cases, backbone' -- Terry Pratchett

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Also, does anybody have any advise on how to measure the proportions I need to mix. I'll probably need to use about 1l of alcohol per bath to ensure the fossil in completely submerged and I'm considering getting a 5l plastic jerry can of the stuff.

  1. Can I just use plastic measuring cups used for cooking (and can I safely use those that we normally use for cooking if I clean and rinse them with water afterwards)?
  2. Would it work if I mark litres and half litres on the outside of the jerry can based on liquid height, seeing as the above instructions seem to indicate approximate amounts and alcohol is also implied as being an extractive agent?
  3. Could I use weight to measure the amount of pyrite-stabilizer to use, rather than using measuring cups?

What do you guys think? What's the best approach here? I don't have a home-lab, so means are rather limited...

'There's nothing like millions of years of really frustrating trial and error to give a species moral fibre and, in some cases, backbone' -- Terry Pratchett

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On 2/18/2021 at 12:34 AM, pachy-pleuro-whatnot-odon said:

And what about Pyrite-stabilizer (from the oldest geological warehouse in the world; not sure if I'd be allowed to mention them here by name, although there's only one place I know of that sells this product)? Or the use of ammonia fumes to stabilise pyrite-bloom? Does anyone here have experience with either of these methods?

 

As I know various members of the Dutch fossil forum have experimented with ammonia-fumes to stabilize pyrite-bloom on their specimens, I asked around there. By what I get from it, they've been using household ammonia solution with, what initially appeared to be, good results. However, the pyrite-bloom always came back. Having looked up a video on how to use ammonia for pyrite-cleaning on YouTube (haven't been able to find one, unfortunately), I came across the below video that explains that not only is the concentration of ammonia in household cleaning ammonia relatively low - which is probably the reason for the limited success experienced - other cleaning agents, including bleach, may also have been added to make the cleaning product more effective. As such, this does not seem like a good approach to combat pyrite disease.

 

 

'There's nothing like millions of years of really frustrating trial and error to give a species moral fibre and, in some cases, backbone' -- Terry Pratchett

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48 minutes ago, pachy-pleuro-whatnot-odon said:

This leaves me with another question: what do I do with the left-over Paraloid that I've used to seal the specimen in? Should I now consider this contaminated and get rid of it, can it safely be re-used, or should I only re-use it for other pyrite-cases? Any advise, @Ptychodus04?

 

I wouldn't use it for stabilization of anything not affected by pyrite. You don't want any extra chemicals added to your specimens than you absolutely must.

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3 minutes ago, Ptychodus04 said:

I wouldn't use it for stabilization of anything not affected by pyrite. You don't want any extra chemicals added to your specimens than you absolutely must.

 

But you'd not necessarily discard it just like that either then. I mean, as I presume you've sealed specimens with Paraloid as part of your own pyrite-treatment multiple times, you don't see any inherent risk of any remaining sulphuric acid leaching out of the fossil into the Paraloid-solution. Am I right in understanding you'd be more concerned out left-over chemicals from the pyrite-stabilizer leaching out?

'There's nothing like millions of years of really frustrating trial and error to give a species moral fibre and, in some cases, backbone' -- Terry Pratchett

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1 hour ago, pachy-pleuro-whatnot-odon said:

Good news, though! Today I received the pyrite-stabilizer, including its instructions, as per below:

 

1491502861_datasheetforpyrite-stabilizer.thumb.jpg.a2256271c350201a51b6a17265895633.jpg

 

While the English text refers to using grain alcohol - i.e., food-grade - the German text refers to "Spiritus" (it's a German product, so I take this as significant rather than an error in translation). From personal communication with the seller, I've been informed that burning alcohol or, indeed, ethanol with MEK and benzoate denatorium works perfectly well in combination with the pyrite-stabilizer. As such, I'll probably go for this option.

 

The downside, however, seems to be that the effects of this treatment, much like that of any other pyrite-treatment, does not appear conclusive, and the piece remains a risk to the rest of my collection. As such, it seems that I'll need to follow these steps after all:

 

This leaves me with another question: what do I do with the left-over Paraloid that I've used to seal the specimen in? Should I now consider this contaminated and get rid of it, can it safely be re-used, or should I only re-use it for other pyrite-cases? Any advise, @Ptychodus04?

That is excellent news!

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58 minutes ago, pachy-pleuro-whatnot-odon said:

Also, does anybody have any advise on how to measure the proportions I need to mix. I'll probably need to use about 1l of alcohol per bath to ensure the fossil in completely submerged and I'm considering getting a 5l plastic jerry can of the stuff.

  1. Can I just use plastic measuring cups used for cooking (and can I safely use those that we normally use for cooking if I clean and rinse them with water afterwards)?
  2. Would it work if I mark litres and half litres on the outside of the jerry can based on liquid height, seeing as the above instructions seem to indicate approximate amounts and alcohol is also implied as being an extractive agent?
  3. Could I use weight to measure the amount of pyrite-stabilizer to use, rather than using measuring cups?

What do you guys think? What's the best approach here? I don't have a home-lab, so means are rather limited...

Safest bet is to use glass, preferably borosilicate (Pyrex). If you use plastic, do a test first.

 

Also, do this outdoors. This stuff is going to stink like crazy until it is set. Please wear disposable gloves and at least a face shield while mixing it.

 

As for measuring, it is always better to measure and mix the smallest amount you estimate you will need. You can always mix up a bit more. Note that if you do mix up a bit more, make sure you homogenize it first before use, that is mix the batches together well!

 

A standard glass kitchen measuring bowl or cup will work fine. Reading over the SDS and manufacture instructions for this stuff it is pretty forgiving.

 

Also, consider putting the specimen in an airtight container with a desiccant for at least 48 hours before treatment. You will get better penetration and bond this way!

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Also, please remember to allow any extra material time to cure before disposal according to your local hazardous materials regulations. Cured it is inert. Uncured, it will kill plants and critters.

 

As an afterthought, you may be able to get very inexpensive laboratory glassware online which might be worth the wait. It appears this stuff is safe for use with Nalgene plastic lab ware, but not polycarbonate. However I freely admit I am unfamiliar with the law over there pertaining to buying laboratory stuff for civilians.

 

Another thought- perhaps reach out to a local school or university with a chemistry department- then you will have professional guidance and might even be able to give a nice demo for the students!

Edited by LabRatKing
Pre coffee typos
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8 hours ago, pachy-pleuro-whatnot-odon said:

 

But you'd not necessarily discard it just like that either then. I mean, as I presume you've sealed specimens with Paraloid as part of your own pyrite-treatment multiple times, you don't see any inherent risk of any remaining sulphuric acid leaching out of the fossil into the Paraloid-solution. Am I right in understanding you'd be more concerned out left-over chemicals from the pyrite-stabilizer leaching out?

I wouldn’t be as concerned about the pyrite the concern is introducing chemicals from the pyrite treatment solution you are using into your Paraloid batch. 

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So, just a bit of a quick update, as I'll come back to this later. But a couple of findings I'd like to add here already:

 

1. As already suggested by the wording of the usage instructions for the pyrite-stabilizer, Nigel Larkin (2011) reports that there is some freedom for fluctuation in the exact proportions of pyrite-stabilizer (monoethanolamine thioglycolate) versus ethanol. That is, based on this I believe measurement of the amount of pyrite-stabilizer used will not need to be so carefully measured. Moreover, he also suggests that isopropanol could be used instead of ethanol, which further widens the amount of "alcohols" available for dilution:

 

Quote
  1. Make a 2% to 5% ethanolamine thioglycollate solution in ethanol or isopropanol.
  2. Immerse the specimen in solution for between one and four hours. Change the solution when it becomes a dark violet colour, otherwise brown insoluble precipitation will stain the specimen.
  3. Wash specimen with alcohol.
  4. Repeat the process until the solution no longer changes its colour when specimen is immersed.
  5. There are some problems with this method. Old consolidants and glues etc will probably be dissolved by the solution which would risk a consolidated or glued specimen falling apart. It is not a very useful method for large specimens or those remaining on display, especially large marine reptiles attached to a gallery wall. Also, specimens can remain stained, labels will be stained and some old iron-based inks may dissolve, both those applied to labels and those applied directly to the specimen. It is therefore wise to photograph all specimens and labels before treatment.

 

As an aside, he also describes how to make a paste based on magnesium silicate that can be used to treat larger specimens that cannot as easily be immersed:

 

Quote
Method 2: Paste application
  1. Make a 3% to 5% ethanolamine thioglycollate solution in ethanol or isopropanol.
  2. Mix equal amounts (1:1 ratio) of the solution and sepiolite (magnesium silicate).
  3. Apply the paste to the affected area and cover it with polythene or aluminium foil to prevent rapid evaporation.
  4. Leave specimen covered for between 1- and 3 hours.
  5. Clean and wash the specimen or treated area with alcohol.

 

Somebody on the Dutch forum also pointed out to me that, according to Tacker (2020), sealing the specimen may not be as much of a permanent solution as I thought it might be, and will still require continuous monitoring (though he doesn't describe dessication prior to impregnation):

 

Quote

Note that the idea of passivating the pyrite surface is distinct from applying various coatings like Vinac, acrylic, polyvinyl acetate, shellac, Butvar, etc. to the surface of a specimen. The rationale behind these coatings is simply to plug holes and provide a barrier. None of these have actually been demonstrated to be impervious to oxygen or water (Howie, 1992b). Data are also lacking to demonstrate that the degassing of these products does not produce oxidizers to further degrade the pyrite surface. Data are lacking to show that the coatings complex with iron or sulfur atoms on the pyrite surface. The utility of these coatings is often justified by inspection, not by any quantitative means.

 

What worries me here is that, if I understand correctly, application with the varnish may actually trigger the pyrite-decay to restart. The same, I believe, is a risk with the use of the pyrite-stabilizer itself, as the filler-component to ethanol seems to be water (i.e., ethanol 96% = 4% water), which is a known catalyst to the reaction.

 

In addition, Tacker also notes that:

 

Quote

The long-term resistance of these coatings to microcracking is not clear. Pyrite and bone apatite expand or contract with temperature changes at different rates. Isometric pyrite expands isotropically, while apatite, a hexagonal mineral, expands anisotropically. The response of various brittle coatings to temperature changes may be cracking or crazing, so that its utility would end the first time climate control systems fail.

 

Which means that the very presence of pyrite might be enough to affect the integrity of the varnish and the fossil as a whole.

 

To me this suggests that, as the condition of the fossil currently seems stable, there's more risk involved in treating it than in leaving it as it is - as @LabRatKing (I'll get back to your other comments later, probably tomorrow - some very interesting points there I'd like to respond to!) already suggested in the very first post!

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'There's nothing like millions of years of really frustrating trial and error to give a species moral fibre and, in some cases, backbone' -- Terry Pratchett

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On 2/26/2021 at 2:40 PM, LabRatKing said:

Safest bet is to use glass, preferably borosilicate (Pyrex). If you use plastic, do a test first.

 

I had originally thought to use a non-branded Pyrex oven-dish with a lid, but decided to go for a glass salad bowl (again, I'd have put a lid on it) after I measured the amount of alcohol I'd need to cover the fossil in both scenarios (one-and-a-half times as much for the oven dish). Now that denatured alcohol can be used, and there's no longer as big a need to be sparing about the volumes of alcohol used, I indeed think moving back to using the Pyrex-dish is not a bad idea, especially if it makes things safer.

 

On 2/26/2021 at 2:40 PM, LabRatKing said:

As for measuring, it is always better to measure and mix the smallest amount you estimate you will need. You can always mix up a bit more. Note that if you do mix up a bit more, make sure you homogenize it first before use, that is mix the batches together well!

 

On 2/26/2021 at 2:40 PM, LabRatKing said:

A standard glass kitchen measuring bowl or cup will work fine. Reading over the SDS and manufacture instructions for this stuff it is pretty forgiving.

 

I was actually considering mixing the solution up in the above-mentioned oven dish on a per-bath basis, measuring the pyrite-stabilizer by weight rather than volume, and the ethanol based on divisions I'd mark on its container prior to first use. As it looks proportions can be very approximate, this would save me from having to use measuring cups and dishes that 1) we currently only have in plastic and 2) would be cumbersome when measuring 1-1.5l of ethanol anyway...

 

On 2/26/2021 at 2:47 PM, LabRatKing said:

As an afterthought, you may be able to get very inexpensive laboratory glassware online which might be worth the wait. It appears this stuff is safe for use with Nalgene plastic lab ware, but not polycarbonate. However I freely admit I am unfamiliar with the law over there pertaining to buying laboratory stuff for civilians.

 

Although the above procedure wouldn't require any laboratory glassware, when I was younger it was possible to buy flasks and other laboratory glassware at a pharmacy in my home-town in the Netherlands. Not sure whether regulations might have changed, but there would be at least one address of how to get by such basic stuff. However, since I now live in France and go over to the Netherlands less regularly due to Covid, I would need to find out whether and where I might find such glassware locally, making it easier if I can do without...

 

On 2/26/2021 at 2:40 PM, LabRatKing said:

Please wear disposable gloves and at least a face shield while mixing it.

 

When you mention disposable gloves, do you mean rubber ones, plastic ones, or textile ones? If plastic ones, wouldn't these be a bit thin? And would they be able to protect against the base, if the solution indeed can't be kept in a plastic container? Moreover, I remember once reading that some of these plastic disposable gloves are more porous than others - which would make them less suitable, I guess (I read this in context of the handling of certain tropical seeds containing strong neurotoxins that can easily penetrate the skin, kill with just a few milligrams, and were at one point commonly used to create tropical necklaces - scary stuff). Manufacturers, of course, don't indicate which is which...

 

As to the face-shield: I was thinking of plastic goggles of the type that entirely enclose the face, and a respiratory mask. This wouldn't be enough? Would a face-shield of the type some people wear against Covid?

 

Are the fumes with the chemicals added for the denaturation the prime concern here, or is that rather the pyrite-stabilizer being a strong base?

 

On 2/26/2021 at 2:47 PM, LabRatKing said:

Also, please remember to allow any extra material time to cure before disposal according to your local hazardous materials regulations. Cured it is inert. Uncured, it will kill plants and critters.

 

I don't know if I quite remember this from my high-school chemistry. So, after I remove the specimen, I leave the solution to stand for a while? Is that what you're saying? Or are there other steps to be taken? Couldn't I do this after moving the solution into a disposal container?
 

On 2/26/2021 at 2:40 PM, LabRatKing said:

Also, consider putting the specimen in an airtight container with a desiccant for at least 48 hours before treatment. You will get better penetration and bond this way!

 

That's a good suggestion, and very similar to what Ptychodus04 suggested prior to impregnation with Paraloid, although he suggested some time in an oven at low temperature. I guess that would work here as well, the main point being to remove all moisture from the specimen.

 

On 2/26/2021 at 2:40 PM, LabRatKing said:

Also, do this outdoors. This stuff is going to stink like crazy until it is set.

 

With the stuff "being set", do you mean while mixing the solution, or over the time that the specimen is being soaked/bathed? I thought I might at least prevent the latter by putting a lid on the dish I'd use as a bath. However, I realised afterwards this may collect the fumes, increasing risk of combustion, if not creating just as much stink when the lid is removed...

 

In any case, the stink might be a bit of a problem at this time, as we've currently got a new born at home. And with the small garden we have, there's no real way to isolate any chemical odours and fumes from the house (which might generally be a problem as we live at the ground floor of an apartment building). Furthermore, if that weren't enough, we live close to the so-called "Oven of Europe" and the sun-shine is growing stronger by the day. With combustible liquids that need to be kept out for multiple hours at a time and very little shade, this might not be ideal... That doesn't mean your point about keeping the toxic fumes outside of the house is well taken.

 

On 2/26/2021 at 2:47 PM, LabRatKing said:

Another thought- perhaps reach out to a local school or university with a chemistry department- then you will have professional guidance and might even be able to give a nice demo for the students!

 

Considering all that you've written - that is, all the things that need to be taken into account when applying this treatment, not to mention waste disposal afterwards (where and in what kind of containers do I get it there?) - this might not be a bad idea. If only we weren't expats over here. As such, we can't turn to our own former schools, but instead will need to find suited ones, conquer the language barrier, and see if they'd be interested in spending what may be a day's worth of work on performing the treatment... Still, it sounds very appealing and would definitely make me feel less uncertain about attempting this treatment.

 

As it is, though, the specimen is providing me with more headaches than I bargained for :(

'There's nothing like millions of years of really frustrating trial and error to give a species moral fibre and, in some cases, backbone' -- Terry Pratchett

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41 minutes ago, pachy-pleuro-whatnot-odon said:

 

I had originally thought to use a non-branded Pyrex oven-dish with a lid, but decided to go for a glass salad bowl (again, I'd have put a lid on it) after I measured the amount of alcohol I'd need to cover the fossil in both scenarios (one-and-a-half times as much for the oven dish). Now that denatured alcohol can be used, and there's no longer as big a need to be sparing about the volumes of alcohol used, I indeed think moving back to using the Pyrex-dish is not a bad idea, especially if it makes things safer.

 

 

 

I was actually considering mixing the solution up in the above-mentioned oven dish on a per-bath basis, measuring the pyrite-stabilizer by weight rather than volume, and the ethanol based on divisions I'd mark on its container prior to first use. As it looks proportions can be very approximate, this would save me from having to use measuring cups and dishes that 1) we currently only have in plastic and 2) would be cumbersome when measuring 1-1.5l of ethanol anyway...

 

 

Although the above procedure wouldn't require any laboratory glassware, when I was younger it was possible to buy flasks and other laboratory glassware at a pharmacy in my home-town in the Netherlands. Not sure whether regulations might have changed, but there would be at least one address of how to get by such basic stuff. However, since I now live in France and go over to the Netherlands less regularly due to Covid, I would need to find out whether and where I might find such glassware locally, making it easier if I can do without...

 

 

When you mention disposable gloves, do you mean rubber ones, plastic ones, or textile ones? If plastic ones, wouldn't these be a bit thin? And would they be able to protect against the base, if the solution indeed can't be kept in a plastic container? Moreover, I remember once reading that some of these plastic disposable gloves are more porous than others - which would make them less suitable, I guess (I read this in context of the handling of certain tropical seeds containing strong neurotoxins that can easily penetrate the skin, kill with just a few milligrams, and were at one point commonly used to create tropical necklaces - scary stuff). Manufacturers, of course, don't indicate which is which...

 

As to the face-shield: I was thinking of plastic goggles of the type that entirely enclose the face, and a respiratory mask. This wouldn't be enough? Would a face-shield of the type some people wear against Covid?

 

Are the fumes with the chemicals added for the denaturation the prime concern here, or is that rather the pyrite-stabilizer being a strong base?

 

 

I don't know if I quite remember this from my high-school chemistry. So, after I remove the specimen, I leave the solution to stand for a while? Is that what you're saying? Or are there other steps to be taken? Couldn't I do this after moving the solution into a disposal container?
 

 

That's a good suggestion, and very similar to what Ptychodus04 suggested prior to impregnation with Paraloid, although he suggested some time in an oven at low temperature. I guess that would work here as well, the main point being to remove all moisture from the specimen.

 

 

With the stuff "being set", do you mean while mixing the solution, or over the time that the specimen is being soaked/bathed? I thought I might at least prevent the latter by putting a lid on the dish I'd use as a bath. However, I realised afterwards this may collect the fumes, increasing risk of combustion, if not creating just as much stink when the lid is removed...

 

In any case, the stink might be a bit of a problem at this time, as we've currently got a new born at home. And with the small garden we have, there's no real way to isolate any chemical odours and fumes from the house (which might generally be a problem as we live at the ground floor of an apartment building). Furthermore, if that weren't enough, we live close to the so-called "Oven of Europe" and the sun-shine is growing stronger by the day. With combustible liquids that need to be kept out for multiple hours at a time and very little shade, this might not be ideal... That doesn't mean your point about keeping the toxic fumes outside of the house is well taken.

 

 

Considering all that you've written - that is, all the things that need to be taken into account when applying this treatment, not to mention waste disposal afterwards (where and in what kind of containers do I get it there?) - this might not be a bad idea. If only we weren't expats over here. As such, we can't turn to our own former schools, but instead will need to find suited ones, conquer the language barrier, and see if they'd be interested in spending what may be a day's worth of work on performing the treatment... Still, it sounds very appealing and would definitely make me feel less uncertain about attempting this treatment.

 

As it is, though, the specimen is providing me with more headaches than I bargained for :(

As someone that has done the expat life and as one that really isn’t qualified by education( I have my job because of my industrial experience, not because of my pissant education) I assure you, do the mixing and curing outside. With a baby around, please do not risk it with this chemical mix. Plus, I assure any compound with “amine” in the name stinks. The real scientists here will agree, I assure you.

 

on the facilities end, I am certain that you will be shocked how accommodating the locals can be. I only was fluent in Castellano ( Spain Spanish) but the educators in Peru, Chile, Mexico, Columbia, and Panama were enthusiastic to have a scrawny Viking looking Americano visit to further science education. I’m making a big assumption about Euro education, but I bet real teachers exist there and are willing to work with you on such an educational project. 
 

remember, science is universal. Race, politics, and religion are not. Those that ask, know. Those that don’t ask, wonder!

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On 2/18/2021 at 1:14 AM, DanJeavs said:

Hi, doesn’t look as bad as you think it does. It just looks like more matrix needs removing thats all. Not sure on peterberough quarry specimens but if pyrite hasn’t been exposed to sea water it should be fine from Decay, dorset material tends to be the worse as far as the uk goes.  Happy to reply to any messages about the way to go cleaning it up.

Dan

 

On 2/13/2021 at 3:01 PM, Ludwigia said:

It wouldn't surprise me if the "black clouding" is pyrite or limonite, which would point to decay. As far as I know, it is not uncommon that finds from this section have pyrite deposits. You could try to remove some of it with careful abrading, but I don't think that it would make all that much difference and may even damage the bone underneath.

 

It seems pretty clear now that the black clouding is indeed due to pyrite decay. I've also just spoken to a collector with decade-long experience collecting from the Peterborough Oxford Clay, and got confirmation that pyrite disease is indeed a concern with pieces from this locality. Although he didn't explicitly mention having observed pieces decaying - in fact, rather stating that pieces from Callovian of the Oxford Clay are usually fine and reporting having held on to a certain pyrite-affected pieces for decades without problem - he did mention that fossils may fall apart even after years of appearing stable...

'There's nothing like millions of years of really frustrating trial and error to give a species moral fibre and, in some cases, backbone' -- Terry Pratchett

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12 hours ago, LabRatKing said:

As someone that has done the expat life and as one that really isn’t qualified by education( I have my job because of my industrial experience, not because of my pissant education) I assure you, do the mixing and curing outside. With a baby around, please do not risk it with this chemical mix. Plus, I assure any compound with “amine” in the name stinks. The real scientists here will agree, I assure you.

I don't doubt your word for it, and very much appreciate your continued feedback on this: it's the only way for me to establish what I'd be getting myself into. For starters, it already indicates how much more complicated it would be for me to do this at home...

 

12 hours ago, LabRatKing said:

on the facilities end, I am certain that you will be shocked how accommodating the locals can be. I only was fluent in Castellano ( Spain Spanish) but the educators in Peru, Chile, Mexico, Columbia, and Panama were enthusiastic to have a scrawny Viking looking Americano visit to further science education. I’m making a big assumption about Euro education, but I bet real teachers exist there and are willing to work with you on such an educational project. 

And while I agree that if you don't ask you might never know, your situation as a guest educator/consultant seems quite different from me asking a school to use their laboratory equipment... To be fair, with how complicated it would be to apply this treatment at home, how expensive the treatment is in general for a piece this size, and how risky the fossil would remain to the rest of my collection afterwards, I'm very much reluctant to go through the hassle. I've therefore sought contact with the seller to see if I can return the fossil.

 

Luckily the seller's reaction was very sportsman-like, stating that they'd of course take the fossil back if I've not happy with it. They also told me that this fossil was collected from the Orton Pit 30 years ago (by a Michael Callaghan, I believe is what they said), when the quarry was still in operation, and has been stable ever since. They keep their pyritic fossils separate until they are confident they are stable, and only then sell them. But, all the same, decay may still set in and happen very suddenly, putting the remainder of my collection at risk...

'There's nothing like millions of years of really frustrating trial and error to give a species moral fibre and, in some cases, backbone' -- Terry Pratchett

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Alexander

 

The pyrite decay effecting the Oxford Clay vertebrate specimens is, in my experience anyway, normally in the matrix not the fossil bone. As the matrix decays due to chemical reaction with oxygen and water, it expands and pulls any attached or internal bones apart (very unfortunate that!). 

 

It looks to me as though your vertebra could have a thin pyrite coating which is quite possibly stable. Another possible reason for the black colour is that it is due to skin residue being mainly melanin, although normally skin residue is patchy and thin.  If it is pyrite and you are worried it could possibly be very carefully ground off with the dremel. Don't forget to wear a proper, close fitting mask if doing so. 

 

Paul

 

Skin residue:

 

DSCF1897.thumb.JPG.21918ea092b9d0c717d06a5fd12c7442.JPG

 

 

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On 3/2/2021 at 1:57 PM, paulgdls said:

Alexander

 

The pyrite decay effecting the Oxford Clay vertebrate specimens is, in my experience anyway, normally in the matrix not the fossil bone. As the matrix decays due to chemical reaction with oxygen and water, it expands and pulls any attached or internal bones apart (very unfortunate that!). 

 

It looks to me as though your vertebra could have a thin pyrite coating which is quite possibly stable. Another possible reason for the black colour is that it is due to skin residue being mainly melanin, although normally skin residue is patchy and thin.  If it is pyrite and you are worried it could possibly be very carefully ground off with the dremel. Don't forget to wear a proper, close fitting mask if doing so. 

 

Paul

 

Hi Paul,

Very interesting to see that you get organic residue on fossils of the Oxford Clay as well, as I've only seen them from the Posidonia Shale (Holzmaden/Dotternhausen) up till now. In this respect, quite the coincidence that your example is also of ichthyosaur vertebrae, as this is the only place I've seen these organic residues on Posidonia Shale material (not that I have too much experience, and have only seen it on pieces others were preparing). Have you encountered, or do you know whether similar residue has been found on plesiosaurian vertebrae as well?

 

In any case, I don't think the black clouding on my vertebra derives from organic residue, as there are clear traces of the vertebra having been affected by pyrite decay: powdery yellow and grey spots, blackening down into the bone itself, and cracking - which I believe is due to the different response to temperature changes between pyrite and fossilised bone (as described by Tacker [2020], cited above), although they could, of course, also have come about when the fossil was still encased in its matrix. All the same, here are some photographs to, hopefully, better illustrate the condition of the bone:

 

1602712988_CallovianOxfordClayplesiosaurvertebrapyrite-damage01.thumb.jpg.e8aa158cca563aa9bd6a71272dbbc674.jpg311053470_CallovianOxfordClayplesiosaurvertebrapyrite-damage02.thumb.jpg.a546af176752a18d047d9a247bfda585.jpg925652087_CallovianOxfordClayplesiosaurvertebrapyrite-damage03.thumb.jpg.a5a7650502b149829a7f4bab97e71c43.jpg863526482_CallovianOxfordClayplesiosaurvertebrapyrite-damage04.thumb.jpg.d49034c358ef64565ea55ce48d41018e.jpg1643901443_CallovianOxfordClayplesiosaurvertebrapyrite-damage05.thumb.jpg.b57d33b10ac0d1e378c9c63d62f63503.jpg1480977148_CallovianOxfordClayplesiosaurvertebrapyrite-damage06.thumb.jpg.d5a9883ca02ccc607351260690298de8.jpg1245406819_CallovianOxfordClayplesiosaurvertebrapyrite-damage07.thumb.jpg.8f5de03e86b8645768668f2f3619ae5c.jpg

 

 

 

Considering the depth of penetration of the pyrite-decay (it doesn't appear to be superficial and really goes into the bone, quite deeply too to judge by the black colouring), using a Dremel isn't really an option. And while I do have some pyrite fossils in my collection, these are mostly self-found and either kept far away from my other fossils, or proven to be stable for over two decades. Though I realise this is less than what is claimed to be the case for this vertebra, the former duration comes from personal observation - not word of mouth and, therefore, in this case, trust in a seller I'm otherwise not familiar with. Also, none of those pieces exhibit the yellow and grey powder indicative of (one-time) pyrite-bloom. Would you put a piece like this along with the rest of your collection?

 

I mean, I feel it's a shame, and even considered may be finding a small, closed display case for it. But, even if treated, it seems the risk of it infecting other pieces in my collection will always remain. And this, when it comes down to it, is a hassle I just can't use right now. So, although it's a pity and I would've liked to find out how treatment with the pyrite-stabilizer works, I'm more and more inclined to return the vertebra to the seller...

'There's nothing like millions of years of really frustrating trial and error to give a species moral fibre and, in some cases, backbone' -- Terry Pratchett

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Hi Alexander

 

Well, looking at the condition of the bone surface, showing the internal structure, I personally wouldn't worry abut pyrite decay on it until I saw the whiskers growing etc. which I don't think will happen if the item is kept indoors at a reasonable level of temperature and humidity. 

 

Interesting about the organic deposits on the Posidonia Shale (Holzmaden/Dotternhausen) fossils. I didn't know about that, except for the organic outline (dorsal fin etc.). 

 

Here is a plesiosaur dorsal centrum from Kimmeridge. This has an extensive black coating (especially on the articular surfaces) which has not shown any sign of breaking down over a number of years. Also here is a partial plesiosaur humerus from the mutabilis zone of the Kimmeridgian of Wiltshire, with black organic deposits. Also shown is a rhomaleosaurus cervical centrum from Whitby with pyrite coating which has remained stable for a decade or more.

 

best wishes

 

Paul

 

 

 

1305952383_plesiosaurdorsalcentrumshowingblackorgainics.thumb.jpg.c7bd965176a28800ad90c0038116204e.jpg

 

 

 

 

1578049269_plesiosaurhumerussectionshownblackorgainics.thumb.jpg.445e7e8907f61b0d4be1d3950ee3952d.jpg


1192531359_rhomaleosauruscervicalcentrumshowingblackorgainics.thumb.jpg.9cb2f7f03302c9c1e54f03c0429a07a4.jpg

 

 

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Hi Paul,

 

19 hours ago, paulgdls said:

1305952383_plesiosaurdorsalcentrumshowingblackorgainics.thumb.jpg.c7bd965176a28800ad90c0038116204e.jpg1578049269_plesiosaurhumerussectionshownblackorgainics.thumb.jpg.445e7e8907f61b0d4be1d3950ee3952d.jpg1192531359_rhomaleosauruscervicalcentrumshowingblackorgainics.thumb.jpg.9cb2f7f03302c9c1e54f03c0429a07a4.jpg

 

Beautiful specimens again! Especially the rhomaleosaurid vertebrae is very interesting: I haven't seen too many of them, and would love to add one to my collection eventually...

Have these fossils been treated in any way (mechanically, chemically, impregnation/coating)?

 

Based on these images I took another look at one of the other pieces in my collection - the proximal part of a plesiosaur humerus from Sandsend, Whitby - which also has some blackened areas that I now think may indeed by pyrite too. Just never really realised until now :zzzzscratchchin:

 

419321816_IndetplesiosaurhumerusheadSandsendWhitby01.thumb.jpg.71a794523408d3bb565029ed5b26223d.jpg807443932_IndetplesiosaurhumerusheadSandsendWhitby02.thumb.jpg.b6592662a56094f3bcae174327433ae1.jpg

 

Now I'm wondering why I'm not worried about this fossil. Is it because I've now had it for a while, it comes from a trusted vendor, the specimen overall seems solid, or because there's no yellow and grey grainy residue, as on the vertebra? I think probably the latter, as this is the type of oxidation that I've familiar with from my own finds and have experienced being stable. That, in combination with my trust in the vendor...

 

17 hours ago, paulgdls said:

Well, looking at the condition of the bone surface, showing the internal structure, I personally wouldn't worry abut pyrite decay on it until I saw the whiskers growing etc. which I don't think will happen if the item is kept indoors at a reasonable level of temperature and humidity.

So you wouldn't be concerned by the yellow spots on the break-surface then either? I mean, I can see the black areas being a stable oxidation product. But the sulphur is what's got me concerned (as well as what might be going on inside the bone because of the sulphur being embedded there)... It's proving a bit difficult to capture on camera, but in real life it's actually quite clearly visible. I've grown to associate these kind of stains with pyrite-bloom, i.e. active and on-going pyrite decay. Also, since I've never experienced the spread of pyrite-decay, I don't quite know how much of a risk this actually is...

 

pyrite-bloom.jpg.a7a33e0bcc6e70516e240768f10a5760.jpg

 

Something else, though: would you agree that this particular vertebra is too big and long for your standard Cryptoclidus? That is, to me it seems more likely to be Muraenosaurus. Do you agree? Could it be something else? What would your impression be?

 

20 hours ago, paulgdls said:

Interesting about the organic deposits on the Posidonia Shale (Holzmaden/Dotternhausen) fossils. I didn't know about that, except for the organic outline (dorsal fin etc.). 

Yes, I was also only familiar with the organic outlines from the Posidonia Shale... until I visited some preperator friends in their workshop and they blasted through some black staining. I was actually quite surprised when they did that (if not to say shocked), as I was under the impression that skin-preservation, even in the Posidonia Shale, is rare. However, they told me that it's actually apparently quite a regular occurrence.

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'There's nothing like millions of years of really frustrating trial and error to give a species moral fibre and, in some cases, backbone' -- Terry Pratchett

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Hi Alexander

 

Thank you for all your observations. Very interesting. I'd love to see some of the preserved organic tissue which is normally blasted away on those H. specimens. 

 

The fossils have been cleaned of residual matrix using a dremel engraver with special tungsten tip (done under magnification, where necessary). Then scrubbed (with nylon toothbrush) with newly diluted glacial acetic acid using very hot water. This only for a minute or so. Then scrub under warm running water until the toothbrush does not show any colour due to matrix being removed. The acid / scrubbing procedure is what I would do on your plesiosaur vertebra to remove any oxidation products and loose material. I then use weakish paraloid painted on with a paint brush.  

 

Love the proximal plesiosaur humerus from Sandsend. That deposit on it is certainly stable. 

 

Yes, I agree the plesiosaur vertebra does look big for a Cryptoclidus  and possibly for Muraenosaurus also. It might be from Peloneustes or another pliosaur. The foramina look too big for Muraenosaurus too. 

 

Paul

 

 

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Although I'm still considering whether or not to keep the vertebra discussed in this topic, I will only do so if I feel the fossil is stable or can be stabilized using low-risk and easily accessible means. As such, I've decided that the pyrite-stabilizer is too dangerous/cumbersome to use around the house (especially with our newborn right now) with too little of a cost-benefit to the preservation of the vertebra. As I don't needlessly want to have dangerous chemicals lying around the house either, I'll be sending it back to the vendor. I'd therefore just like to thank everyone who helped me look into its application, especially @LabRatKing and @Ptychodus04, who've shown great patience in sharing their wisdom and years of experience with me. Thank you!

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'There's nothing like millions of years of really frustrating trial and error to give a species moral fibre and, in some cases, backbone' -- Terry Pratchett

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8 hours ago, pachy-pleuro-whatnot-odon said:

Although I'm still considering whether or not to keep the vertebra discussed in this topic, I will only do so if I feel the fossil is stable or can be stabilized using low-risk and easily accessible means. As such, I've decided that the pyrite-stabilizer is too dangerous/cumbersome to use around the house (especially with our newborn right now) with too little of a cost-benefit to the preservation of the vertebra. As I don't needlessly want to have dangerous chemicals lying around the house either, I'll be sending it back to the vendor. I'd therefore just like to thank everyone who helped me look into its application, especially @LabRatKing and @Ptychodus04, who've shown great patience in sharing their wisdom and years of experience with me. Thank you!

Always glad to help. I totally understand the hesitation. I was pretty meticulous about chemicals (as well as other dangerous objects that hunters have in the house) when my boys were little. Now they are going on 18 and 19 (and are hunters themselves) so the needed extreme care is a thing of the past in this house! 

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18 minutes ago, Ptychodus04 said:

Always glad to help. I totally understand the hesitation. I was pretty meticulous about chemicals (as well as other dangerous objects that hunters have in the house) when my boys were little. Now they are going on 18 and 19 (and are hunters themselves) so the needed extreme care is a thing of the past in this house! 

Thanks for understanding! It means a lot to me!

 

As I now seem to be down to either Paul's approach or yours, I've been looking into Iron Out. However, I've only been able to find ready-made solutions or toilet cleaner tablets. Would you know if either of these work?

'There's nothing like millions of years of really frustrating trial and error to give a species moral fibre and, in some cases, backbone' -- Terry Pratchett

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2 hours ago, pachy-pleuro-whatnot-odon said:

Thanks for understanding! It means a lot to me!

 

As I now seem to be down to either Paul's approach or yours, I've been looking into Iron Out. However, I've only been able to find ready-made solutions or toilet cleaner tablets. Would you know if either of these work?


Anything that is a rust remover should work. I would go with the ready made solution over the tablets.

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