Pyrite Preservation Experiments

[BlazeXploder]

Okay, recently found a really badly hit specimen of pyritised fossil wood, which appears to be infected with some sort of bacteria. I looked through the collection, and my fears were realised, the entire batch was disintergrating.

So, me and Fossily99 have embarked on a series of tests to see how best to preserve Pyrite. Theory and other threads are all well and good, but im 15. I dont have access to ammonia and acids and fancy resins. So, household tests are being conducted on pyrite, from 1999, 2009, 2010 and 2011.

Some of the pyrite is infected by bacteria, eating away at them, and some of it is ancient. Some is less than a week off of the beach.

So, stay posted for test results and pictures.

TEST 1: Sealing with weak PVA

Initial Results: This test has been rather unsuccessful. It hasnt held the piece together at all. Although, it is a very weak solution.

TEST 2: Washing then Sealing with weak PVA

Initial Results: Cant tell it from the untreated pyrite, so whether it is actually protecting or not is not clear. It has, however, changed the feel of the fossil.

TEST 3: Spraying with WD-40

Initial Results: The longer the WD-40 is present, the better the effect. This is seen by the side facing down on the main sample being better off after the WD-40 had evaporated; it took much longer for the underside.

TEST 3b: WD-40 Submersion

Initial Results: I had accidentally left a fossil in some of my WD-40, and it appeared to have cleaned it of all loose material. It looked brilliant and hadnt dissolved, but did appear to have absorbed the WD-40, or its escaped as vapour. So im making a photo documented version.

TEST 4: Washing then Spraying with WD-40

Initial Results: Very very promising. this one has been documented start to finish by photography, which I plan to do for the others. It has produced a good finish, and is true of the initial WD-40 test. Picture is quite large, so here is the link: http://i304.photobucket.com/albums/nn174/ohham/WD40TestA.png

TEST 5: Best of the WD-40 experiments, then sealing with Weak PVA

TEST 6: Clear boot polish (one specimen already 1 year old)

Test is very very clearly working, with very little decay, although some is clear. The untreated side of this Oxynoticeras shows a good amount of decay, so it has slowed the decay. This is spitshined in (using water, not spit, however).

TEST 7: Liquid polish

Initial Results: Not great, the polish is black, so it has died the ammonite slightly (and also my hands). A good cover is difficult to get. It advertises waterproofing, and I had some, so it was worth a test. I dont hold much hope.

TEST 8: Air tight bag

Test didnt work. I had a sealed bag of pyrite from the 1999 trip and the 2010 trip, neither show a good slowing decay, however, they have slowed it slightly. I pin this on the fact that it is hard to keep a seal, and if its opened, the fossil suffers.

TEST 9 (Fossily99): Paraloid

TEST 10 (F99): Beeswax

TEST 11 (F99): Varnish

TEST 12: Syllica Gel packed into an airtight container

NOTES: This is the hardest to get a hold of, however, some shoes come with pouches of this stuff in them. Im going to ask a shoe shop.

TEST 13: Double layer weak PVA

Initial Results: Not a great look on the fossil, removes some of it...stone effect. However, it certainly is easy to see where the gaps in the coat are.

TEST 14: Improvised Oil (Vegetable Oil)

Initial Results: Obscured my view of the fossil, and leaves an oily film, but Im sure it will stop the decay effectively. Photo Documented.

Any suggestions, please post below. I'd like to get as many specimens treated as possible. The tests initial results will be posted immediately, results after aging will be posted sometime in the future.

Edited June 7, 2011 by BlazeXploder

[jkfoam]

What a great set of experiments. I am anxious to see the results.

Don't forget to do a "control", one test in which nothing is done to the specimen.

Good luck,

JKFoam

[BlazeXploder]

O.o! I almost forgot a control group! thanks!

Im doing most of the tests on the 2010 group, the 1999 group is pretty far gone. the best results will be repeated on the 2011 batch.

[Ammojoe]

I plan to coat half of a choosen specimen with one substance, and the other half left blank, therefore it can easily be determined what the effect of the substance is on the rate of reaction with the Pyrite. Although this test is a decent start, there are a lot of factors which need to be tackled, for example; Pyrite collected from different localities, even on the same beach, can alter the rate of deterioration, as well as the fossil being treated. For instance, coating one fossil, a Promicroceras (Ammonite) may not deteriorate as quickly as another species, for example; Echioceras (Ammonite). To complicate matters further it can depend on the type of fossil, Belemnite, Ammonite, Vertebra, Crinoid etc. If anyone has any advice on how to combat these issues, then please say it would be appreciated. Does anybody have any experience using Ammonia? I'd love to know what results have been achieved using this method, or any other method you know of.

Kind Regards,

Joe

[BlazeXploder]

I agree that this is very important, and it needs addressing. And indeed, your test will herald better results, but the initial testing im doing is to stop general pyritic decay. I shall try and do a test similar to yours as soon as possible.

[tracer]

to me the basics are this -

pyrite +water +oxygen becomes iron sulphate +sulphuric acid +sulphur dioxide.

or something like that. the degree to which the material is acted on is very dependent on the exposed surface area of the pyrite, so when you have the forms with "granular" textures with lots of surface area, they seem much more susceptible to rapid degradation. but another key point is that the reaction is self-catalyzing due to the sulphuric acid. so if the problem's already started, and you don't get the sulphuric acid neutralized, then sealing the surface isn't going to stop what's going on. and really, you need to prevent both oxygen and humidity from accessing the pyrite, long term.

[BlazeXploder]

Yeah, unfortunately, most households dont contain such things. These experiments are just an attempt to preserve the fossils as well as possible, and hopefully I will be able to keep them as long as possible.

[piranha]

From the National Park Service Museum Handbook Part I:

What is pyrite disease?

Pyrite disease is common in some fossil collections. Pyrite disease results from the oxidation of iron pyrite (“fool’s gold”) in a fossil. Pyrite can be present in bone, invertebrate shell, or plant fossils. The oxidation of pyrite will affect microcrystalline or framboidal pyrite far more than it does larger crystals. The resultant iron sulphate (FeSO4) causes fossils to crumble as the crystals grow and expand. The damage is preventable, but irreversible once it begins.

How can I protect my specimens from pyrite disease?

Keep the fossils in a stable environment. Temperature and humidity fluctuations promote pyrite “rot.” Consolidants, coatings, or adhesives can be of use only if they are introduced to the specimen under vacuum conditions to coat all surfaces internally and externally. Even carefully conserved specimens can explode spectacularly due to pyrite “rot” building up under the protective skin of preservatives. The only way to slow the oxidation is to lower the relative humidity. If the reaction has not started, keep RH at 45% or lower; if it has started, reduce it to 30% or lower. It’s possible to clean the reaction products off the surface of a specimen. This requires a very specific procedure and specialized training. Untrained personnel can easily inflict further damage to, or destroy the specimen.

What should I do if I notice pyrite disease?

Remember: Prevention is always better than treatment.

Follow these steps:

Remove the specimen from its storage environment to a work area.

Brush away and discard the dry powdery reaction product with a

dry, soft brush. If you’re fortunate, you may need to do nothing

more than rehouse the specimen at this point.

If you can’t keep the RH below 45%, and pyrite problems exist,

you’ll have to upgrade your storage environment. Possible

solutions:

Build a microclimate within the storage cabinet using desiccants

(see COG 1/8 “Using Silica Gel in Microenvironments”).

Create an anoxic (low- or no-oxygen) environment (see COG 3/9

“Anoxic Microenvironments: A Treatment for Pest Control”).

For a collection of known reactive specimens, anoxic film

enclosures will help slow the reaction. But be aware that it

never stops.

For a large collection, consider installing climate-control

equipment for an entire case or cases.

What else should I consider when confronting pyrite disease?

Cross-Contamination

The pyrite oxidation reaction liberates sulfuric acid. This can damage other specimens and storage materials. Do not let other specimens touch infected ones. Also, encapsulate specimen labels (don’t laminate them) so that they are not in direct contact with the specimen.

Susceptibility to pyrite disease

A fossil’s susceptibility to pyrite disease may depend on the types of rock in which it was preserved. Holmberg (2000) noted a good example of this principle:

Two fossil whale skeletons containing pyrite were obtained from Miocene clay. They were found in different states of preservation, though they had been stored under identical conditions. One of the skeletons was embedded primarily in light-colored clay dominated by the mineral smectite. (Smectite has a high absorption capability and low pH.) The other embedding medium consisted of other clay minerals, mainly kaolinite and illite. (These minerals have a neutral pH resulting from the presence of carbonates, which work as buffers.) Pyrite in the fossil bones from smectite-rich clays was more susceptible to deterioration after exposure than bone containing pyrite preserved in clays dominated by other clay minerals.

[pleecan]

Nice write up Scott

Peter

[Diplotomodon]

A very thought-provoking topic here...fascinating.

This is just in my opinion, but perhaps an admin should pin this? It's a common problem that I'm sure a lot of people would like to solve in some degree. Ben's testing and Scott's info look like valuable resources.

[Fossildude19]

This is a great topic!

Thanks for posting it, BlazeXploder!

Well done!

Regards,

[tracer]

A very thought-provoking topic here...fascinating.

This is just in my opinion, but perhaps an admin should pin this? It's a common problem that I'm sure a lot of people would like to solve in some degree. Ben's testing and Scott's info look like valuable resources.

there are several other topics like this on the forum. if you use a search engine to search for pyrite rot, some of the top hits are to the forum already.

[BlazeXploder]

thanks for the write-up! I havent thought of using silica gel. Ill ask for some at a shoe shop next time I can and add a new test on it.

The issue with Microclimates and proper fossil techniques is the tools necessary, as well as the chemicals. Getting chemicals is near impossible in england aftert the 7/7 bombings, and microclimates require sensors and such like. I hope to find a quick fix.

[Roz]

Experiments are really fun too!

Now is the WD 40 the oil? Just want to make sure

I am following this..

[Kosmoceras]

Thanks! Has helped a lot!

[BlazeXploder]

Experiments are really fun too!

Now is the WD 40 the oil? Just want to make sure

I am following this..

WD-40 is a Water Dispacement fluid, designed to unstick mechanisms. When I was 5, I had a very rusty climibng frame, and my dad used it to get rid of rust. The liquid is like oil. Ill post pics of the recorded experiments, as WD-40 is going VERY well. It actually appears to improve the look of the fossil, even if it isnt child friendly. It also cleans off the white dust if you do submersion.

[Kosmoceras]

Why not put it in oil? Oil has no oxygen in I believe.

[BlazeXploder]

Why not put it in oil? Oil has no oxygen in I believe.

Ill find a good container and get right on it!

[Kosmoceras]

Ill find a good container and get right on it!

Hope it works!

[BlazeXploder]

Just put a sample into a pot, ive got before/after pics for this one.

[Roger]

You mentioned that you are 15 and do not have access to some materials. A substitute for a dessicant - crystal cat litter. Go to the store and look for a crystal style cat litter (Tidy Cat Crystals?) The crystals ABSORB moisture and odors. Before we got Lane cabinets at our lab we would place Tidy Cat crystals in the tops of shoe boxes and then close the doors on the wooden cabinets holding the specimens. It was a temporary fix but it did keep the humidity down in a very enclosed space.

[trend]

A very simple way to create a low to no oxygen environment is to use a food saver vacuum system. There a number of types and prices, but they all work by removing the air and then sealing. If you don't like the idea of them being in plastic bags, some have jars where you attach a small tube and it will also remove the air. You can make a mount inside the jar and have the best of both worlds, a glass display specimen in a no oxygen mount. You can buy them at a retailer, or grocery store. here's your selling point for your mom to buy one for the family: Maybe your mom would also enjoy using it to freeze meals and prevent freezer burn.

[BlazeXploder]

Hmm..never heard of either, but ill certainly look into the cat litter idea. Im afraid I cant be going and getting stuff that it isnt reasonable for people to have in their houses, so no vaccuums (unless I did a makeshift one)

[Xiphactinus]

Hmm..never heard of either, but ill certainly look into the cat litter idea. Im afraid I cant be going and getting stuff that it isnt reasonable for people to have in their houses, so no vaccuums (unless I did a makeshift one)

Not sure what stores they have across the pond, but here is an inexpensive vacuum:

http://www.basspro.com/FoodSaver-FreshSaver-Handheld-Vacuum-Sealer-or-Accessories/product/10225231/-1679449

[Terry Dactyll]

For the experiments try and just use the Echioceras... Ive had a couple of Promiceras that have been fine for 20 years so they may have a slower reaction to the oxidation process, perhaps having a different chemical makeup/composition... Some echioceras I have thrown away after 3 years...

Did you ever notice the 'ammonite assemblages' (that wasnt explained so well) of Echioceras that sold on ebay a few years ago... they were lots of Charmouth pyrite ammonites glued together in a chunk on a wooden stand and the gaps between them covered in pyrite filings glued on... Some people paid hundreds of pounds for these, I bet they have started reacting and falling to bits by now