About pyrite disease

[Savvas]

Greetings! I just learned about pyrite disease and got really scared.

Is it really common to happen to a fossil?

Is it present this possibility for every fossil? How do I recognize it if it starts happeningnon a fossil?

How to prevent it from happening? 

How do I stop it if it happens?

Please help me because I start to become paranoid....

[bcfossilcollector]

Hi Savvas. 
 

When exposed to an environment with high levels of humidity, pyrite can indeed rust. The best way to preserve pyrite specimens is to keep them in as dry an atmosphere as possible. If necessary use a dehumidifier. If pyrite rot/disease does occur, you can try using a dessicant like silicone gel packs (?)to help remove moisture from the container the pyrite specimen is stored in. Once damage has occurred it’s irreversible, all you can do is halt further damage to the specimen or in extreme cases prevent the specimen from gassing out and damaging items in close proximity to the item. The phenomenon of pyrite rot gassing out is what is sometimes referred to as pyrite disease. I would google museums and pyrite for more comprehensive instructions as to caring for pyrite and what to do to halt pyrite rust if the process has started to occur in your collection. Remember any chemical treatments to halt pyrite rot should be done under the guidance of an expert!  Good luck!

[bcfossilcollector]

Just as an addendum. Pyrite that is compact and crystallized is actually fairly stable although one still needs to be careful as regards humidity. Pyrite that is microcrystalline in nature is highly unstable. Both should be, as stated,stored in dry environments!

[Savvas]

12 minutes ago, bcfossilcollector said:

Hi Savvas. 
 

When exposed to an environment with high levels of humidity, pyrite can indeed rust. The best way to preserve pyrite specimens is to keep them in as dry an atmosphere as possible. If necessary use a dehumidifier. If pyrite rot/disease does occur, you can try using a dessicant like silicone gel packs (?)to help remove moisture from the container the pyrite specimen is stored in. Once damage has occurred it’s irreversible, all you can do is halt further damage to the specimen or in extreme cases prevent the specimen from gassing out and damaging items in close proximity to the item. The phenomenon of pyrite rot gassing out is what is sometimes referred to as pyrite disease. I would google museums and pyrite for more comprehensive instructions as to caring for pyrite and what to do to halt pyrite rust if the process has started to occur in your collection. Remember any chemical treatments to halt pyrite rot should be done under the guidance of an expert!  Good luck!

Is pyrite present in all fossils? And how does a fossil that starts having the oxidation look like?

[bcfossilcollector]

Pyrite is a fairly common mineral especially in sedimentary rock. Having said that I don’t think it’s necessarily present in all fossils. Certainly not in huge quantities. Other members of the forum have a lot more knowledge regarding the chemical composition of rock types. I’ve had examples of pyrite on display for years without having any discernible problems regarding rust. Pyrite rust looks red/deep orange.  I forgot to mention, always try to handle pyrite specimens with gloves. The same is true for any metallic substance that oxidizes easily. 

Edited April 20, 2023 by bcfossilcollector

[Savvas]

4 minutes ago, bcfossilcollector said:

Pyrite is a fairly common mineral especially in sedimentary rock. Having said that I don’t think it’s necessarily present in all fossils. Certainly not in huge quantities. Other members of the forum have a lot more knowledge regarding the chemical composition of rock types. I’ve had examples of pyrite on display for years without having any discernible problems regarding rust. Pyrite rust looks red/deep orange. 

And would a specimen with the disease start to be crumbly in the part that it is infected?

[bcfossilcollector]

Yes. Eventually it will crumble. In unstable pyrite deterioration can be rapid. All of the pyrite specimens I’ve collected have not exhibited any problems. Pyrite formed as sedimentary concretions  have a tendency to be unstable   I know pyrite suns can have a problem  where rot is concerned. I have yet to experience this although my pyrite is kept in a fairly dry environment. 

[JBkansas]

14 minutes ago, Savvas said:

And would a specimen with the disease start to be crumbly in the part that it is infected?

Turns white and crumbles:

https://www.zoicpaleotech.com/pages/pyritefossils

[bcfossilcollector]

@JBkansas Excellent article! I hadn’t heard of the Pyrite Stop solution. Thanks. 

[JBkansas]

1 hour ago, bcfossilcollector said:

@JBkansas Excellent article! I hadn’t heard of the Pyrite Stop solution. Thanks. 

Per a prior discussion (see below), it may not be 100% effective.

 

 

[jpc]

back to the original question... most fossils are not pyritic and this pyrite stop should only be done to pyrite fossils...those that have that golden look that is typical of pyrite.  

 

 

[doushantuo]

some of you may like:

Tacker, R. Chris. 2020. A review of “pyrite disease” for paleontologists, with potential focused interventions.

Palaeontologia Electronica, 23(3):a45. https://doi.org/10.26879/1044
palaeo-electronica.org/content/2020/3159-pyrite-disease

edit:spacing

 

1044pyr.pdf

Edited April 21, 2023 by doushantuo

[t-tree]

Some pyrite fossils decay faster than others I had some that went within a year and some that have no signs of decay 20 years later, but I did notice pyrite fossils from some locations are more prone to decay.

 

John

[Bobby Rico]

I something I noticed other the years been on the forum is Pyrite fossil seam to decay when they placed in Tupperware or plastic airtight bags this I think is because the specimen is  not 100% dry. I think the lack of air accelerates the decay by creating a humid conditions . Just my thoughts .

 

Edited April 21, 2023 by Bobby Rico

[jpc]

2 hours ago, Bobby Rico said:

I something I noticed other the years been on the forum is Pyrite fossil seam to decay when they placed in Tupperware or plastic airtight bags this I think is because the specimen is  not 100% dry. I think the lack of air accelerates the decay by creating a humid conditions . Just my thoughts .

 

Indeed... put a bunch of silica gel in there and that will help a lot.  When the gel turns pink, take it out and bake it til it turns blue.  

This will keep moisture out of the tupperware and the fossil.  

 

[Bobby Rico]

10 minutes ago, jpc said:

Indeed... put a bunch of silica gel in there and that will help a lot.  When the gel turns pink, take it out and bake it til it turns blue.  

This will keep moisture out of the tupperware and the fossil.  

 

That’s good advice. I myself don’t use tupperware We have an old draughty house but no damp . So I never had this problem with in my collection. I hope other members see your advice because I remember quite a few post with “ I just opened some Tupperware and I found my fossil has crumbled “ . Cheers Bobby 

[RuMert]

BTW I heard that soaking in Zaponlack (completely submerged) for a week heals and prevents pyrite disease. Somebody may want to test it

[Ludwigia]

6 hours ago, RuMert said:

BTW I heard that soaking in Zaponlack (completely submerged) for a week heals and prevents pyrite disease. Somebody may want to test it

I did that particularly with my finds from the Provence. It holds for a few years, but the effloressence occurs nevertheless over time and you have to scrub and redo.

[pachy-pleuro-whatnot-odon]

17 hours ago, RuMert said:

BTW I heard that soaking in Zaponlack (completely submerged) for a week heals and prevents pyrite disease. Somebody may want to test it

 

I've also heard that Paraloid B-67 works well, as it is hydrophobic and therefore keeps moisture away from the specimen. The varnish, however, starts to disintegrate after a couple of years, leading the specimen to be exposed and in need of renewed treatment. The best solution, I think, though somewhat out of reach of most collectors, would be to use a Pyrite Stopper. This will remove the core triggers for pyrite disease and should equally last multiple years. There's no long-term solution, however, that doesn't require monitoring and renewed treatment. Currently, I'm trying out submersion in Paraloid B-72 after heating at 200 Celcius in an oven for a batch of pyrite cubes from Winterswijk...