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Apologies for the dramatic title. I thought it sounded cool and stuck with it even though 90 + 80 + 80 is only 250 . Anyways... This past 30 days, I decided to make it a point to check out some new spots. I won't be living in Austin soon, so I thought it would be good to branch out and scout some new locations with potential. I've found lots of creek-worn mosasaur bits and pieces over the past year. I'm ready to find things in situ, and, one day, something articulated. It's a tall order, I know, but I feel like it's the next step and really the ultimate goal I've always had. So, the first step towards this objective was to find locations and, of course, take a look. This is what I saw! Location 1. Austin Chalk: In my usual Ozan stomping grounds, I've come across a variety of fossils ranging from the Eagle Ford to the Ozan itself. Included, was an assortment of spectacular Austin Chalk invertebrates along with the occasional and highly sought-after mosasaur vertebra. They can be readily distinguished from their Ozan counterparts by their yellow-orange preservation and lack of pyritic elements. Honestly, I come across them just as commonly as I do Ozan verts, so I took this to be a sign that the Austin Chalk could be a good bet. In Austin, it's a pretty wide formation with lots of members to look into. I did some research and found a place with some potential. When I arrived, it was a hot afternoon. I picked up my backpack and swapped my school notes out for a rock hammer and a couple of icy bottled waters. Walking down a little trail, I came across the first large exposure of Austin Chalk in what I believe to be the Dessau member. Literally within the first minute, I had to take a double-take at a white glint on the ground. "Surely there couldn't already be a shark tooth," I thought to myself as I kneeled for a closer inspection. Sure enough, it wasn't just a shiny piece of shell; it was indeed the enamel to a bleached tooth from the king shark of the Late Cretaceous seas, the infamous Cretoxyrhina mantelli! Thankfully, it popped out in one piece. A recreation of the tooth in situ and after extraction. I poked around the rest of the surrounding exposure. There were a couple of mangled echinoid bits and gastropods, but not much else, so I continued on to search the main creek. Unfortunately, the only apparent path forward was along a narrow and steeply banked feeder stream. Many of you will know that navigating through these can be a real pain. The brush was densely packed and smelly stagnant water had to be avoided with every step. There were thorny vines dangling from each limb and I was constantly tasked with picking off the burrs that snagged onto my clothing and in my hair. Last year, I was in a similar situation when I was suddenly attacked by a hive of wasps (don't worry, I managed to avoid getting stung too much). It's a fun story to tell friends now, but I must admit that the thought always crawls back into my mind when I am in a position that's a bit difficult to get out of in a hurry. Anyways, after about twenty minutes, I took the final hop over a fallen tree to get to the main creek. It was nice to breathe in the fresh, open air as I sat my backpack down and took a rest, of course, with my eyes perusing along the limestone bed. After the brief sit-down, I began to notice the beauty of the area I was in. The air was filled with the drip-drop of water leaking from the fern-covered bank and the reflection of the greenery was simply mesmerizing. I couldn't help but snap a quick photo. A beautiful, hidden place away from the city. Though, not too far... there's a shopping cart wedged in the gravel just out of frame. In terms of fossils, this place was loaded. Just about everywhere I stepped, I was standing over piles of clams and oysters along with the occasional baculites segment. I didn't bother taking any of these with me, however, as I have plenty already. I noticed there was a decent amount of chert as well, so artifacts were on my radar when I came across a preform. A little farther down the creek, I found a nice ammonite fragment. I didn't intend on keeping it, but sometimes it's nice to have something to hold so I took it along with me. By now, much of the afternoon had come and went. It was about time I turned around and faced the prospect of navigating my way through the dreaded feeder creek in reverse. As I was coming to a stop, I saw a girl walking along the slanted banks of the creek who almost certainly did not enter the way I did. I tried my best to get her attention without spooking her (keep in mind I look and smell like a swamp monster at the moment). She was nice enough to come close to the limestone ledge and introduce herself as I trudged my way through knee deep waters towards dry land. Turns out, she's a local who often hikes by the creek. We chatted for some time and I ended up giving her the preform and ammonite fragment, hopefully inspiring a future hobbyist. After explaining the situation I was in, she laughed and pointed out a trail that led back to the road. When I climbed out and exited the trail sore and tired, I kicked myself. My car was right in front of me. I could have taken this path from the beginning, but instead I took the road never traveled and boy did it make all the difference. Location 2. Ozan Formation: Although many of the mosasaur verts I come across are from the Austin Chalk, a significant portion are still from the good ole Ozan. With that in mind, I took a trip to a creek I usually don't hunt that had a decently-sized exposure. Something in a book tipped me off to this particular site, so I had high hopes. The trip from the road to the waterway wasn't as troublesome as the feeder creek from the week before, but it was still a challenge. I worked my way along the dirt bank to a place I could safely enter the waters when I saw what I was more so wary of. Across the lazy stream was a tent set up along a slope with a clothesline and shopping carts around it. On the initial drive to this spot, I did take notice of the pronounced homeless presence in the area. From the cover of the trees, I took a moment to scope out the tent and the surrounding area. The last thing I wanted was to have an unexpected encounter in a secluded place like this. Luckily, it seemed nobody was home, so I entered the creek, though making sure to have my rock hammer visibly in hand. When I approached the first gravel bar, I was greeted with tons of broken down blocks of Ozan shale and various Austin Chalk fossils. Curious, I started splitting the blocks open to see what the area had to offer. Each one was filled with heart urchin spines and plates! Most were fragmented and all were extremely fragile. Still, I took this to be a good sign. After hours of splitting the loose slabs, I finally found a complete irregular urchin. It's a definite upgrade from the half of one I had found a while back in the Ozan (though that one did have a nice red color). A compressed heart urchin. Looks to be Pliotoxaster/Hemiaster? It may appear round, but it is totally flat! The slab splitting continued with some compressed ammonites and enchodus teeth, but not much more, so it was time to move on to the main event. As I walked the rest of the gravel bar, however, I was forced to once again stop in my tracks. Lying in the mud right in front of me was, by far, the largest mosasaur vertebra I had ever seen in person. It had the preservation of what I assume to be Austin Chalk (of course as soon as I return to the Ozan). The underside of the vert was badly weathered, but it was, nevertheless, far heavier than any others in my collection. Plus, I only need one decent side to show in my picture . Gargantuan mosasaur vertebra. I wonder how long the whole lizard was. Welp, there's really no better motivator than something like that, so I took the short walk to the main exposure. A large expanse of creek bed was Ozan shale ripe for the picking. I got straight to working chiseling out every strange thing just poking out of the ground. Most of them were only oddly shaped pyritic accumulations, I'm guessing originally bivalves and poop. Now and then I would come across a Hamulus squamosus worm tube or piece of fish bone. The bed was a little difficult to see as the lack of recent rain meant that the detritus and algae had yet to be washed away. I didn't find much in the water. Thankfully, the dry parts of the bed were easy to probe. Eventually, I came upon something unmistakably bony. Before I could stop myself to snap a photo, I was already digging. It popped out easily and was instantly apparent of being mosasaur, the very thing I was seeking most. Frantically searching for a continuation of the vertebral column, I spotted what I thought was the head of the next vertebra behind. In my mind, I could see it all right in front of me. The ultimate prize was right there! Just some minor excavating and I'll have done it! Perhaps in theme with fool's gold, I was fooled by the imprint of the very fossil I had just pulled out . I was bummed out for a second, until I had time to realize that this was my first ever mosasaur vert found in situ! Out popped my first in situ mosasaur vert! Cleaned up, it is a real beauty. The color of the cuboidal pyrite outgrowths looks amazing when moved under the light. "Fool's gold" is a real disservice as far as names go. And with that, the sun was already starting to set. The finds of the day. 2 mosies, a flattened echinoid, a Hamulus squamosus tube, an Austin Chalk ammonite, and an Austin Chalk Exogyra tigrina. Location 3. Ozan Formation: After crossing such a major milestone, I had no choice but to head out for the Ozan again once a brief rain had passed. This new location was similar to number 2 in that it was a large expanse of Ozan creek bed. Unfortunately, the route to reach it from the road was a treacherous one. I didn't intend on swimming across a sudden deepening of the creek waters, so I had to search along the steep banks for ways to traverse the barrier. There was somewhat of a flattened trail along a slope with various obstacles that seemed the most doable to me. For the most part, I side-stepped my way across, hugging the dirt and tree limbs to avoid losing balance or putting too much weight on the unstable ground. Now and then, I'd have to cross through a bush that would replenish the population of burrs covering every part of me. By that point, I couldn't have complained too much as things were going relatively smoothly. That is until I made one misstep and had to quickly catch myself by snagging an exposed tree root. Regaining my composure, I heard the rustling and sliding of a plastic bag followed by a loud splash of water from underneath my feet. I usually carry my dirty pair of tennis shoes in a plastic bag since I swap between them and water shoes on my excursions. Now they were just a white shimmer far beyond reach. I hopped off the bank and landed on firm ground. Most of the bed was readily exposed to the air. There was a high density of deer and raccoon tracks. I was entertained most by the shale claw marks I saw at the bottom of shallow pools that I interpreted to be raccoons taking a refreshing swim. From way up the creek, I even caught a glimpse of a coyote jumping from out of the foliage. He sniffed around a bit before noticing me and darted off the other way. I settled down to catch my breath and inspected broken bits of Ozan shale nearby. Pretty soon I spotted the first regular echinoid I've seen in the Ozan. Unfortunately, it was too fragile and didn't survive the journey home. A regular echinoid and a mess of urchin spines surrounding. This portion of the Ozan is rich in echinoid material, though heavily compressed and often very fragile. Denture clams are the other most common find of which fragments can also be seen here. After some rehydration, I got up to start looking for bone. It took some time, but I eventually found a peculiar specimen sticking out of the shallows. It was too suspect to ignore, so I began excavating. Spongey thing as originally found. I was hoping it would be a rib or something, but it just didn't look right. The pores of the cancellous bone were much larger than what I was familiar with for reptiles and the thing didn't seem like fish at all. Typical for fossils in this layer, there was pyrite all over. However, there was an additional mineral I hadn't encountered before. Encrusting the entirety of the underside were selenite(?) crystals in prismatic shapes. As I dug deeper and deeper, the form continued on. The spongey thing was long and had curvature. There was another short one layered just underneath it intersecting close to the hammer. If it's vertebrate, I have no idea what bone it would be. I suspect it's invertebrate in nature. Revealing more of it showed that a separate, shorter piece was present just underneath. Both structures were flattened, fragile, and had to be removed in chunks. From what I could tell, their spongey structure remained consistent across the entirety of their lengths. Once extracted, I searched the surrounding space, but found no sign of continuation. Post extraction I was completely stumped by what I had found. All I could think was spongey, pores, spongey, pores. I am embarrassed to admit it took me way too long to cut off the "y" and realize that it's likely a sponge. Pore bearing (porifera) is about as accurate as you can get when describing it. So, I settled with that as my final guess for what this mystery structure could be. Though, this is still up for debate, so let me know if there are any opposing opinions. From there, I took a couple of paces before stumbling upon the next thing of interest. It was a robust black protrusion with some apparent symmetry. Okay, if the last thing was pseudo-bone, surely this had to be the real thing. As per usual, there was pyritic encrusting on it. From how it was positioned, it was hard to say how long it could be - if there was much more to try and dig out. I got to chiseling and it popped right out within the first few swings. Instantly, I knew I had once again fallen for some pseudo-bone. That being said, it was the first time I had found carbonized wood in the Ozan. I don't usually keep fossil wood, but this guy is interesting enough to warrant it. A pyritized deposit of coal, pretending to be a mosasaur rostral. The fossil wood with a pyritized denture clam and Serratolamna(?) tooth on top. A piece of an artifact and irregular urchin on top. The clam on the right is a cool optical illusion. It's only 3/4 of an inch tall. Here and there I made some other nice smaller finds. A fragment of an artifact, some shark teeth, and an even better flattened irregular urchin to name a few. Though, I had spent a lot of the recent weeks hammering away at things in creeks, so I thought it would be best to call it early and head home to have a nice meal and reflect on my prizes. No articulated mosasaur bits, but a great many lessons learned and special memories to reminisce upon in the future. I know I'm preaching to the choir with this one, but there are few things as magical as traveling alone and exploring a side of the outdoors you hadn't encountered before. It's hard to explain, but I love just parking somewhere and walking into a part of the brush where few people go, if ever. It's freeing in a sense. But for now, I've creek walked way too much. I'm gonna go hunt a roadcut or something

Hello, in my quest for jet and amber I came across this piece this week in an old mine. This is the first time that I have found a piece of good jet covered with its bark totally pyritized over several millimeters. I find the result very pleasant but I fear for its stability in the months or years to come! This dates from the Turonian and the abandoned mine is in Languedoc Roussillon in France!

Back in January I decided to check out the Ammonite Beach at Lake Texoma for the first time. The site is well known for its giant Duck Creek ammonites that can be found scattered all over the shoreline. The weather was surprisingly not that bad despite it being the winter. The water level was quite low and there was plenty of good ground to search along. During my time there, I had some success in finding my own ammonites which gave me an excuse to finally put my rock hammer to use. I stumbled upon some echinoids, but none of them were in all that great of condition, so I might need to head back again in the future to solve that issue. Lastly, there were some interesting fossil finds of stuff I didn't expect to be there (more on this later). A lot of the ammonites that come out of Texoma are encased in a decent amount of rock/mud. I have very little experience in any sort of prep work, so cleaning them up was my chance to try something new. My tools were a bit primitive (hammer and kitchen ice pick which got destroyed), but I managed to clean up an ammonite without breaking it for the first time. I didn't think to take a before pic, but the whole face was covered in hard matrix much like on the reverse side. Unfortunately, I made a lot of white scratch marks on it, but I'm mostly just relieved that it came out in one piece. Apologies if this hurts the eyes of any more experienced ammonite preppers reading this . It was a long process and I decided against cleaning up both sides as that seemed too risky of a prospect. I'm fairly certain it is one of those Mortoniceras given the pointy tubercles covering it. Once I finished that, I watched a Lake Texoma video made by "The Fossil Fiend" on YouTube. Even though this was a few weeks after my trip, my exact ammonite showed up on his video! I couldn't believe my eyes when he was pointing right at it as shown in the screen grab above. It's a perfect match to my second pic. What a funny coincidence! My brother and I hauled up a much larger ammonite as well. I'm going to try harder to not scratch this one. I managed to get some work done before winter break ended, but there's still a long way to go. This is gonna be a fun summer project. Beyond ammonites, I came across a plethora of smaller finds that I view to be just as interesting. Below is an overview of the coolest ones: 'A' and 'B' appear to be Leptostyrax macrorhiza? and Cretolamna appendiculta? respectively. I heard that sharks teeth were rarely found at Texoma so coming out with two of them in a single hunt was really exciting. Additionally, I found a piece of what I think is some sort of Cretaceous fish tooth (C). It's black and fairly reflective. A cross section of the tooth is like a football in shape. In other words, there are two edges that run opposite of one another from top to bottom while the rest is rounded. I tried to capture a photo of this, but had some difficulty. Here are some closeups: Something very unexpected was the large amount of pyritized microfossils to be found all over the shoreline, interspersed with the ammonites and echinoids. I had never heard of pyritized microfossils being at Texoma, so I was a bit confused as to why they were there and in such great numbers. It really did feel like I was back in the Waco Pit. I found pyritized ammonites, bivalves, and gastropods. I'm curious if anyone knows what formation they're from. I am under the impression that the whole area is Duck Creek formation, so is that simply what happens to smaller shelled fauna in that layer? The pyritized ammonite 'E' I have below somewhat resembles Mortoniceras, but I'm not sure if they come from vastly different points in time. 'F' reminds of me of a miniature Oxytropidoceras. 'D' is a pyritized heteromorph ammonite. I don't think heteromorph ammonites are known to come out of the Duck Creek, at least in larger form, which makes me think these pyrite fossils are from a different period. Really curious to hear what you guys think of all this! I covered them in wax to prevent degradation. That made it a little harder to pick out details, especially through a camera unfortunately. Here's some closeups: The last handful of fossils are just a sample of the fish verts and tiny oysters I came across: All in all, it was a fun trip - very different from the other sites I have been to. After learning of the huge presence of pyritized microfossils there, I get the impression that it's like having two sites in one; the Waco Pit and the more traditional Texoma famous for its beautiful ammonites/echinoids. Paired with its proximity to Post Oak Creek, I will definitely being taking more drives up there in the future when I'm back in DFW. As usual, let me know if you would like any additional close ups. Thanks for reading!

Hello, I've recently collected some fossil wood from the London Clay. However, I have heard that it is prone to pyrite 'disease'. I've cleaned the wood with water, and plan to keep them with packets of silica gel to reduce humidity. Will this be enough to prevent pyrite oxidation occuring? I've just attached some photos of some of the wood that it can be seen on. There is also this white-coloured material on this bone. Is that anything to be concerned about? Many thanks

One is pyritized and I have no clue what it is. The other I’m thinking is a plant? Found alongside loads of crinoids

This one has been sitting in my "interesting but I have no clue" pile for a while. When I found it, I was splitting limestone laying in the stream. I've found that when you split limestone, immediately after splitting you'll get a couple moments of a sharp looking specimen before things start to oxidize. The limestone is a very dark gray, or almost black color. You either see black limestone or white calcite pieces while splitting. I split this particular piece open and right in the middle was a 3-4 cm long, 8 mm wide gold looking rectangle in the middle of the flat broken limestone. I thought I wouldn't get to recover it, but one hammer hit later it popped out and I was able to save it. I do find that plants in the limestone seem to get the gold or pyrite type preservation. I've found one small straight shelled cephalopod preserved like this. But overall, it's very rare here. I have maybe 3 or 4 larger pieces of what I'd called pyrite type material I've recovered. Below are some stacked microscope photos of it. The scale in the first photo is 1 mm for each mark. You can see the grain that runs left to right. This looks like wood to me, but I haven't had that confirmed before. The next two photos are a view looking from the bottom to the top of the first photo. What has me most curious are the perpendicular grain marks that are found in this area. They don't seem to just be on the outermost layer, as you can see more deeper. I'm not sure if this is some sort of perpendicular crystal pattern, or it's just the shape of the original material that was replaced with the mineral. And maximum zoom. A stack of 12 microscope images taken through the lens in the same area of the above photo. And that's it. Is this a small piece of woody material that was preserved in the sea? I wonder if vinegar would clean this up or destroy the mineral as well.

I would be grateful for help with identification of this ammonite. It is Sinemurian and found in Gloucestershire.

Hey everyone! I thought I'd share a few of my finds from the past couple months and get yall's opinions. Over winter break, I went back home to North Texas and did some searching around Ammonite Beach at Texoma and the NSR with my family. At Texoma I had a nice time hammering out a few ammonites, collecting teeth, and surprisingly finding lots of smaller, pyritized ammonites that I did not expect to be there. The NSR was a bit slower, but I at least got a nice Squalicorax as shown in the pics below. Since school has started, I've been down in Austin. I've been finding the usual stuff, but the pyritized disk I've attached is new to me. I'd love to hear what you guys think! Austin Finds: Pictured above is the pyritized disk and a pyritized clam found in a gravel bar next to what I believe to be an Ozan exposure. The area has a decent amount of the pyritized clams and other marine fossils that I assume are cretaceous in age given the local geology. My initial reaction was that it could be a vertebrae, but the bulging center and distorted shape throws me off. It has very apparent concentric rings on both its faces. In pics 1 and 3, you can see that underneath that outside layer there is a lot of pyrite. Parts of the edges are also pyritized while other sections have an iron concretion look to them. The face shown on pic 2 resembles and feels like petrified wood. I suppose this could be a pyrite sun, but I'm not seeing anything too similar to what I have on google images. Super interested in what you guys have to say! Texoma Tooth (left) and NSR Tooth (right) Left (Leptostyrax macrorhiza?): Pretty tooth found by my little brother at Texoma in the Duck Creek Formation. Did some quick googling and found that Leptostyrax macrorhiza was in that formation and saw some pictures that were similar to what I have. Right (Squalicorax): Had a bit of a slow day at the NSR, but managed to at least find this at the end of my cold, muddy adventure there. It's preserved very nicely. Looks like Squalicorax to me. Would love to know the species. If you guys would like any additional closeup pics feel free to let me know! I might share some of my other finds later on, but I don't want to inundate the forum with my rocks lol. Thanks for reading.

Hello all, I hear that crinoids from a site known as "Corey's Bluff" of Crawfordsville, Indiana tend to be susceptible to pyrite decay. I don't know if this is a pattern but I've noticed a few crinoids from this location having black spots that I'm told are pyrite. Could I ask any members who've dealt with these crinoids or heard of this speak about their experiences? I noticed @Harry Pristis for one has some very nice crinoids from this site with such spots. I'd really appreciate any and all thoughts. Thank you.

Hello, I went on a trip to Lyme Regis, U.K. last week and came back with some lovely pyrite ammonites and a small ichthyosaurs vertebrae. However we also found this. I’m not sure it’s a full pyrite piece (6cmx6cm) as there is an impression of an ammonite however there are these pyrite cone shapes. Are these just Echinoids Or have I got really lucky with some shark teeth? (very unlikely I know!). I only came across this last one via the National History Museum fossil app which has a picture of a Hybodus delabechei teeth and it looks very similar from a top down view on to the tooth cusps. There are also a number of black specks which look like fish scales which I have seen in coprolite fossils, but may well not be! Really hoping someone could help with an ID or any ideas… It’s got me baffled. Many thanks in advance. Kind regards N

Hello, I'm looking at this ~5cm Ohio Silica Shale Paraspirifer bownockeri. I was wondering if such bright gold coloration indicates "enhancement" of the pyrite by harsh prep, acid treatment or brass wire brush? Or is this just the natural color of some specimens? Many pyritized Paraspirifers I see are more grey or silvery (though I have indeed seen such gold ones). Other pyritized fossils as well seem to typically be more the silver/grey color, and as far as I can tell Pyrite itself is generally paler than a vibrant gold. Thanks.

After quite literally stumbling upon this deposit today we had quite the day looking for gonaitites.

Few gonaitites I prepped today

Another find from Saltwick Bay, this time very recent. I'm guessing that the main chunk is fossilised wood of some sort, but I'm stumped by the small (~1cm diameter) patch of pyrite that exhibits very regular dimples (see images 1 & 2). Any ideas?

I have cracked open some slate with pyrite and have some interesting finds. The pyrite is quick to rot and most of what I have found in my area thus far seems to be made of or encased in sediment with much pyrite. If I brush the pyrite layer it simply destroys the thin film of what was. Am I just stuck until I get my stereoscope? I will have my air pen and sand blaster soon. I was thinking perhaps just air blast it? I have tried to file it down with my diamond block and wondering if I should get a much finer grit and polish to give it a smoother surface but I would only be getting the ones that happen to be perfectly placed on that level. Below is a picture of what I assume to be charnia in said slate rock preserved as pyrite. I'm not interested in the charnia ( in regards to this post) but rather the macro and micro trace and preserved critters. Some look spectacular with tails that look like a birch tree seed and the body of a see slug/Ankylosaurus, only macro and micro.

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've been cleaning up a few boxes with devonian fossils from the past few months and came around this nice little fellow. I cleaned him up and gave him a paraloid treatment to preserve the pyrite. It is a complete specimen of a Bactrites sp. from the Matagne shales ( Frasnian, late Devonian ) from Belgium, both phragmocone and body chamber are preserved. They are a little unusual, as the do not belong to the nautiloids as his first appearance might suggest but they have their own subclass and are considered to be the ancestors of the ammonids ( they have a ventral syphuncle like all the ammonoids ) Fragments of them often pop up from the shales, but I rarely find them complete. This one is going in the display cabinets

Hi everyone, wanted to show off this piece i found a few months ago in Normandy, France. Far from an expert but as far as i could tell it's a piece of wood that turned into charcoal and where the bark pyritised, it's about 7cm tall. Had trouble finding similar specimens online, is this a common occurance? (The wood part is very shiny because i had to glue it because it started to become very cracked and unstable after a few months)

Hi all, I recently decided to buy the below plesiosaur vertebra after having seen it for a long, long time. It dates to the Callovian of the Oxford Clay and was found at Peterborough. I suspect it may be attributed to Muraenosaurus leedsi, as it comes from a cryptoclidid plesiosaur, but is both larger and more elongate that the typical Oxford Clay Cryptoclidus vertebrae I'm familiar with. Supposedly coming from an old collection, it has a blackened exterior that doesn't cover the entire piece, with the more common buff colour visible underneath. As such, I expected the dark colouring to be simple dirt or may be some kind of consolidate that could be removed using acetone to leave a nice and clean looking vertebra in its place. However, since having tried acetone cleaning, the dark colour doesn't come off - suggesting that it isn't surface dirt and any consolidate, if present, is not soluble in acetone. I've also noticed that the black colour doesn't spread equally across the vertebra, which is most noticeable towards the top on the front face (first image) where one half of the vertebra is buff, the other black, with a hard separation in between. As this mottled pattern can be seen in other places on the vertebra as well, I thought that, may be, the vertebra might have been in a fire and have become covered in soot. I find additional support in the latter hypothesis in very brittle pieces of bone in one or two spots, with a charcoal-like grainy texture. Lastly, then, I've spotted a tiny edge of yellow staining/infill in an area where the vascular structure of the bone is exposed, with some white infill in an area adjacent - which I've now started worrying might be pyrite. My questions to you are: Origin of the blackening: Does the black clouding of the vertebra look like natural preservation? Related to the above: could the black clouding be due to pyrite decay? In contrast: could exposure to fire cause the clouding pattern seen on the vertebra? What consolidate might have been used to result in such colour patterning? Cleaning: Is there a way to remove soot from a fossil? Has anyone tried? Other than removal by acetone, what other ways might I try to remove an old, darkened consolidate? In case of decayed pyrite, I don't think there's anyway to clean the surface, other than, may be, through careful sandblasting, is there?

Found in Michigan, recently, I came across coal and shale full of flecks along a river full of carboniferous fossils and stones. Much of the coal will still have bits of visible calamites within them, if it helps. I don't have much experience with pyrite, but have with chalcopyrite. The coal I believe is effected by chalcopyrite by the outside looks but the inclusions are more pale, silvery-gold in some areas rather than a deep gold, brown, or iridescence. Is this likely just chalcopyrite, or can the two grow together like this? Are there other ways I can tell whether it is pyrite vs a yellow/gold chalcopyrite, in general? (Apologies for the pic quality, the water was reflecting the shines off the inclusions and was hard for the camera to focus on the whole thing.)