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Hey all! When I went on a collecting trip in the Hell Creek Formation in Montana, there were many iron concretions, and I've noticed that some specimens from there appear to be iron-stained. This makes me wonder if pyrite could be among the minerals involved in fossil preservation there. Are some of the bones found in the Hell Creek pyritized, and how could those be distinguished from others preserved differently? If so, do those Hell Creek specimens ever develop "pyrite disease," and what would be the warning signs to look out for? Thanks so much for sharing your knowledge!

Hi all, A couple of years ago I acquired a lovely pair of plesiosaur propodial bones from Lyme Regis. It was a matched pair of both humerus and femur. Today, when I was looking to make space in my cabinet for a new acquisition I had made, I discovered some odd dust next to the humerus that, on inspection and to my horror turned out to be pyrite bloom! I immediately removed the specimen from the cabinet, checked the other podial and nearby fossils, and used a tooth brush to brush of the most direct traces of pyrite decay. But the question is: what now? How do I ensure the propodial's preservation, and make it safe for display again. Should I store affected piece in an open or closed container? I suspect the latter, together with silica beads to consume any excess moisture might be best right now. But how do I get to the point where I can take it out again? Any suggestions are welcome. From my own thread on this topic I know of the existence of pyrite stopper, which sounds ideal for this situation. But I've also been warned that this is quite a hazardous solution and am therefore afraid of trying this out myself. So, part of the question would be whether someone offers pyrite treatment as a service, of knows of someone who does. Thanks in advance for your help! @Ptychodus04 @DanJeavs @paulgdls @RuMert and others

I started off rinsing with water until I realized it was causing all the fine detail to disintegrate away (I saw little suction cups on the tentacles!). I think it'a pyrite disease? Is it? I dunked it in a bowl of vinegar and it it still there now, hoping to stop the water damage and it seems to have halted the rapid deterioration, but now I'm concerned about the acid causing damage. What should I do next? I read online that a phosphate treatment may replace the escaping sulfur and stop the oxidation and that a recommended field treatment would be common fertilizer. How the heck would I apply fertilizer to a fossil? I do have some chemicals in the house for art in furniture restoration, but definitely not pure phosphate. Again, this is foreign territory. Any help would be greatly appreciated, thank you all! Location: Annandale, Virginia within the Virginia Gold-Pyrite Belt. My neighborhood is in the Cambrian period, but there was a geographic displacement from the Blue Ridge Mountains into Northern VA, not sure how/if that figures into the scenario.

Hi all, I recently acquired the below fossil, a pair of articulated jaws, purportedly from Pachystropheus rhaeticus, still with teeth, found at Garden Cliff/Westbury-on-Severn. Whether I wasn't paying proper attention when I bought it or just hoping there wouldn't be any pyrite on the piece, when I received the specimen it turned out that there are quite numerous pyrite-crystals growing to the side of the fossil. As it's quite an unusual piece that I'd rather like to keep, I'm now looking for people with experience with pyrite from the Garden Cliff location. In essence, I'd like to ask how stable the pyrite from this location typically is: whether it decays into a black oxidation product or starts blooming with time. How concerned should I be about the stability of this piece? The pyrite itself looks relatively clean right now, so I'm thinking the rock on which the fossil sits hadn't been exposed for too long. But any advice would be welcome. @Welsh Wizard @Pterygotus @DanJeavs

My fossilized bivalves seem to be turning gold in some areas, and some parts have chipped off . Is this "pyrite disease"? Is it due to being on wooden shelving? I wouldn't say my climate is particularly humid. My great uncle gave these five to me when I was seven, so they are special and I would like to save them None of my other fossils or minerals are exhibiting these signs?

Hi I have a question regarding storing and safely displaying a pyrite fossil. I have read a great deal about pyrite disease so I know that's something to be carefull of and I have read you best keep them away from humid and store them in an air-sealed container. And now that's where I am heading with this question, what is all considered as a possible air-sealed container? I am currently keeping my pyrite ammonite (Pleuroceras Spinatum from Buttenheim in Germany) in a small transparent box as seen in the photo below, but is this good enough? Is this air-tight and will this protect the fossil from possibly falling victim to pyrite disease? Or do you guys recommend other ways to display it? Safer ways... Than the second part of my question... Some might already read that I am currently working on a new fossil room, and since it's nearly finished I was wondering wether it was safe to house pyrite fossils in said room when I take some precautions. Cause along with my fossils the room will contain 2 aquaria: one freshwater aquarium with my Polypterus retropinnis, and one brackish water with my Gymnothorax tile. (Also before transforming into a fossil room this room used to be one of the 2 aquarium/terrarium rooms in the house and it contained at one point 12 aquaria and we never really experienced problems with moisture.) As precautious measure I was planning to add a small dehumidifier just to be safe, but so my second question. Would it be wise to house a pyrite fossil in an air-tight container in this room even if it has a dehumidifier in it? And should you also recommend me to preserve the fossil in some paraloid on the fossil, I still have a bottle with 100 ml of paraloid. I would like to hear your opinions on the matter. Which container to use? To preserve it with Paraloid or not? And if I can move it the to new fossil room or if I should leave it in my old display case in my living room? Thank you in advance!

Hi all, So a few weeks ago now I went to the location Carniol in France to look for fossils. And we found lots! Most of the finds are pyrite ammonites, but we shouldn’t leave out all the belemnites and little shell steinkerns we found. All the fossils are from the Aptian stage of the Early Cretaceous, and apart from the belemnites all have been replaced by pyrite. So I've already taken out all the belemnites and rinsed the clay off of each one (they’re looking gorgeous right now!), because their shells are not made of pyrite (and seem not to require any special treatment). By the way, does anyone know why only the belemnites are not replaced by pyrite, while all the other fossils are??? But now comes the question of all the pyrite fossils. All are very small. Some were found already starting to “rust” (I suppose this is due to pyrite disease?), but most are still in good state. Nearly all are still partially covered in dry clay though, and (just like it did with the belemnites) I suppose it will come off very easily as soon as it comes in contact with water. But, here is where I am a little worried: Rust is due to the oxidation (—> oxygen) of iron. And in water there is oxygen too, and more of it than in air. Therefore I’m scared that rinsing the pyrite fossils will accelerate the process of pyrite disease and make them “rust” more quickly. So what should I do to clean the fossils? Is it okay if I simply rinse them off? Or is that a no-go? Or maybe I should do it in a special manner or with specific substances? And, finally, what do you think is the best way for me to handle these fossils so that they “survive the pyrite disease” the longest possible? I know that there are a few ways with some weird chemicals to treat them, but I’m only a kid with limited equipment, money and experience, so I’m not able to do anything too intricate or acquire very funky chemicals. I’ve also read that apparently there are two different types of pyrite? How do I know which one my fossils are, and is there anything I should know more about it? Thanks in advance for your help to all those questions! Max

I have a sand dollar that is mostly covered by pyrite. It still has most of it's luster. I have read about pyrite disease and am wondering what I should do to help preserve it. I have also read that having pyrite in the fossil showcases my affect other fossils. Is this true? What should I do to bring back some of the luster? And how would be a good way to seal it to prevent the turning or ruining of the fossil and others?