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Not sure if these resources have been shared before, but this is how professional collection managers deal with pyrite disease/decay/rot. From the LA County Natural History Museum: https://lacmip.github.io/emu/documentation/pyritedecay/ June, 2019 Volume 11 of the Geological Curator is devoted to the subject: https://www.geocurator.org/images/resources/geocurator/vol11/geocurator_11_1.pdf Fenlon and Petrera's paper on page 9 has a good discussion about various coatings which were historically used as well as what the current best practice. It seems the current best practice for museums is storage in low oxygen microenvironments, i.e. storing it in a cardboard box with plastazote foam, putting in an RP System(R) Type K oxygen scavenger, and sealing in Escal (TM) Neo barrier film.

It’s a sad day. Years ago, I collected a microconch and macroconch of Scaphites so. from the Late Cretaceous Arcadia Park Formation in Dallas, TX that were preserved in pyrite. I’ve collected dozens of pyritized ammonites from this particular site and all have been stable. These ammonites appeared to be stable for about 15 years until one day the pyrite decay started. I noticed it a couple days ago and soaked these specimens in iron out to try to stop the decay. Alas, my attempts were unsuccessful and both specimens crumbled to powder. Beware pyrite, even if you think it’s ok…

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....

Good afternoon! Everything I find currently is from the North Sea, and I do end up finding a lot of bones with the spongey part (cancellous?) exposed through breakage or wear. Some crumble at a light touch, and most of these have a distinct odor like decay, not horrendous but definitely notable, even months after they've dried up. Does the smell indicate, like I have been assuming, that they are subfossilized, and/or possibly younger specimens? When I think back to natural history museum visits, I don't recall that smell, and not every fossil bone I have found has the smell. Some of the teeth I found do as well. Thanks in advance for any info, it is mostly just a question of curiosity.

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I have a bunch of petrified/coalified wood from Mazon Creek and have started a process to decrease the reactivity of the pyrite and sulphur in them. Thought I'd describe the process and results in case it is helpful to anyone else. Some of them are fairly quick to form decay and even create lovely hairy crystal gardens of possibly Pickeringite or Halotrichite. Here is an earlier post about that. Here's some images of the cool crystal hairs that formed awhile back. Anyway here's my process that I've started on a few items. Not at all sure if this is the best process but thought I'd try it as an experiment and see what happens. It is an adaptation of recommendations by Reiner Mielke. Any suggestions or critiques would be great. I'm currently at Step 4 with the first batch and debating about Step 5. Step 1: Neutralize in water with some baking soda. (I notice my pieces really fiz a lot and some of the material breaks a part in this reaction so one may need to be careful with fragile items.) Step 2: Dry in the oven at low temperature for several hours. Step 3: Immerse in WD-40 to displace all the water. Step 4: Let dry Step 5: Two options and I haven't decided between the two: One option is to immerse in motor oil. (This is the Mielke approach) The other option is to spray with Fluid Film (a lanolin product in a spray bottle to prevent rust) Then let dry.