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Found this coral head today where I’ve found other agatized coral in the Tampa Bay area in FL. To me it looks suspicious, it has a slightly blue color around its edges and has some botryoidal formations on the outside. It’s not super lightweight though, so I don’t think it’s hollow (or completely hollow). Does this look like it’s worth cutting? Is it likely to have any voids or botryoidal formations inside based on other agatized corals you guys have seen? recorded-478291984396.mp4

This ongoing journey begins as many do, with an accident. While trimming down matrix from my collection to reduce weight, in this instance a piece of the Aust bone bed, I accidentally sliced right through an ichthyosaur vertebra that I didn’t realise was there hidden in the rock. After the initial annoyance wore off, I realized that the internal texture of the bone was pretty nicely preserved and that gave me an idea, maybe I could make a histological section of the offcut piece of the vertebra. I have always wanted to learn how to make thin sections and this gave me the catalyst, so I emailed my the lab technician in my department (I study Paleobiology for my PhD) and next thing I know I was scheduled for training on how to use the departments thin sectioning and polishing lab. I hunted through my collection for a few fossil pieces that I could use as practice and decided on two Yorkshire belemnite fragments, as I have more complete examples and I thought that the rings of the belemnite would make an excellent subject. I am going to wait until I have more practice with the technique, and also have an opportunity to CT scan the block for posterity before I go grinding away what remains of the vertebra. The first test pieces: The process for making thin sections is relatively simple though it requires at least two days for the resin to cure. First you cut a wafer off of the specimen using a specialist saw which produces a very smooth cut surface. The resulting wafer from the smaller belemnite tip: Then you can bond the cut surface of the wafer to a frosted glass microscope slide using epoxy resin. These are then placed in a clamp to cure Two days later, I was introduced the thin section machine, which contains both a cutting wheel and a grinding disk with the arm attached to a micrometer. The glass slides are mounted in a vacuum chuck on the arm and then passed through the blade which cuts off excess material leaving only about 500-600 microns of sample material bonded to the slide. Next the arm is maneuvered to the grinding wheel and with successive passes ~20 microns at a time are ground off the sample until the remaining layer is only about 100 microns thick. At this point the sample is translucent and polarized light gives an idea of the crystal structure of the belemnite! Unfortunately, due to some issues with the resin mix these first two attempts didn’t turn out great but for the purposes of learning I was shown how to polish them anyway, first using a 9 micron diamond suspension which after repeat use reduces the sample to approximately 60 microns and removes the scratches from the grinding disk, then with a 3 micron suspension which does the majority of the actual polishing. Polishing slides: And here’s what the initial results look like under the microscope, I’m looking forward to trying the technique again and improving, as well as figuring out how to attach my camera to the microscope to take better pictures. The growth-rings in the belemnite are very apparent and in the one where I cut through the phragmocone end you can clearly see the siphuncle! Beautiful belemnite growth-rings from the larger specimen: The siphuncle on the edge of the phragmocone: The rings preserved in the smaller specimen: The rings at higher magnification: I’m excited to get to improve my technique and I have a few ideas for other pieces to test with. I will update this soon with more as I keep working at it. Please feel free to ask any questions you have and I’ll try to answer them. Thanks for reading, Benton

I recently purchased a Stihl TSA 230 battery powered cut-off saw. I know several people on here use Stihls so I was hoping to get some input. The battery fits in snug, but still dust accumulates inside the battery compartment during cutting. I can shake most of it out afterwards but there's always some stuck to the sides of the compartment and the battery. I wiped it all out of the compartment and off the battery the first time, but it took a while to do so thoroughly, and I was worried about even having a lightly damp rag near the battery. Is it a big problem to have some residual dust left in the battery compartment? Just trying to take care of this thing well from the start, it's my new favorite toy and was not cheap.

A while back, I wrote this article/page because I was fascinated with all the different rock hammers, especially Estwing. I had some experience using them, and I liked them more than others. https://fossil.15656.com/resources/geological-hammers-and-tools/ Surprisingly on a website where I write about many paleontological topics, this page has been the most visited by people using Google. I hope it's useful for anyone seeking out a hammer.

I recently acquired a small Araucaria cone and I am wondering what the general opinion on cutting/polishing fossil pine cones. Should it be cut to show off the internal structure or is it best to just leave it as a whole specimen? How do you feel about modifying fossils in general to enhance aesthetic, rather than scientific, value? I am interested to hear the Fossil Forum's opinions.

Hello, here is my experience with my cheap little tile saw purchased 12/22/2020. That´s the setup at the moment: Some modifications and additions: - I rotated the saw by 180°. This is first to reduce spraying into the face. And second it is much easier to "feed" from the back. You also have much more visual control producing an even cut in this way. Electric switch is now at the back right, which is no problem. - Glued two thin plates (2 mm) onto the table, touching the blade. The table has a big gap at one side of the blade to allow tilting of the table. That´s a nuisance, specimens can get easily jammed in this gap during feeding, resulting in very uneven cuts. The line where the two plates (nearly) meet is also a very good visual guide. Cutting height is now 32.5 mm. - Build a hood out of wood and toilet paper bags, not many words needed. - Saw is sitting in an old backing tray. - Cable connection needs to be a little bit lifted with a small rock, otherwise it is bend outside the anti-kink device and is dipping into the water... (faulty design!). - A lamp was already there. Results: - The blade cuts extremely well, the motor is powerful enough. Cutting one of the larger fossils only takes half a minute or so. - It consumes a lot of water, dripping onto the backing tray. No problem, just suck it up with a sponge cloth regularly. Used about 2-3 liter for 8 specimens, refilling at least after every cut! - The motor becomes warm rather quickly, it takes about 250 Watt running idle. It is rated for 600 Watt and 10 minutes short-time duty. I don´t think, it would survive that... So I have to let it cool down regularly, when it becomes very warm to the touch (maybe about 50° C surface temp.?). - The cuts are quite uneven for my taste. This comes from the fact, that the diamond-bearing ring is relatively thick compared to the metal disc carrying the diamond-bearing ring. But that´s the way it is. The better your fine motor skills, the smoother the cut. Mine are not good... - Highest specimen I have cut was 69 mm high. This resulted in a little "knob" in the middle, had no problem to grind it away with the saw blade. - Saw is situated in the basement, have no sink there. This is also a little bit of a nuisance, but that´s again the way it is. Using a bucket instead. - It is potentially dangerous. I have nearly 30 years experience with such kind of saws. I you have none, I strongly recommend personal and practical advice of someone experienced with these kind of machines and work. - Safety googles are a must, of course. - Gloves may be good, but such diamond blades are quite smooth, no real danger for accidental serious injuries by the blade itself. - Ear protection can be worn, but it is not extremely loud and when you are using it only for a few minutes every week or so, it does not matter. - Biggest danger are flying rocks when feeding the saw improperly. But this never occurred to me in 30 years. Just feed it correctly. Here are the results of today´s early morning work, box is 30x20 cm, biggest specimen to the lower left: Feel free to ask anything. Franz Bernhard

Ok, I proved it possible to make polished slabs of substantial size (ca. 50 cm2) without any machine, purely by hand, in an acceptable time and of good quality and with things I already had, especially flat plates. Grinding and polishing media had to be bought, of course. All of this can be done on a desk in an apartment, no serious noise or dust production involved, just some sludge . Only one problem remains - you need an as flat as possible surface to start with. Such flat surfaces are usually produced with rock saws. For rock cutting, I have only experience with professional equipment. However, such rock saws are expensive, heavy, noisy etc. What are the low-cost options for the occasional saw cut? First, forget the angle grinder. Second, what about tile saws? They are cheap, around 50-60 Euro, and far less than that for a used one. Quite lightweight and portable, about 10 kg. But they are made for cutting thin tiles, maximum cutting depth is about 35 mm. I am used to "rotate" specimens on the saw blade, so this can be doubled (Attention, this rotation can be dangerous if not done properly and results also in a surface not as flat as you might desire!) I don´t have experience with a tile saw yet, has anybody of you? And has someone used such a saw in an apartment? Has anyone tried to make parallel cuts with such a saw? Other thing: What about cutting specimens already in the field? Has someone done this with low-cost equipment? Maybe you can use a tile saw with an DC/AC converter connected to your car? I think, that´s all what I like to know at the moment . Thank you! Franz Bernhard

Hello Fellow Fossiliers!! So whilst on a field trip with the OUGS in Lyme Regis the other day I stumbled upon this rock which has a bivalve and a partial (what would have been huge) ammonite in it. As you can see the ammonite has undergone mineral replacement and has crystallised, seen as its not really structural intact from the outside and seems to only be 1/16th of a complete fossil would this look good if I sliced it in half to open up the inside? And, if so, seen as I have no real prepping/cutting tools to speak of how would you recommend I go about it? I have asked a local mason to run it through their machines, they quoted £30 max depending on how hard the stone ends up being, I would prefer to do it myself and have the tools and ability to do it again should i need to. It stands roughly 18cm high on its end as picture. Thank you all in advance for your opinions and advice!

So I'm aiming to visit some of the Altamira Shale (Monterey Formation Shale) exposures in my city and try to find some fossils in fallen shale pieces. However, I simply cannot find a good way to split shale (I also have small rocks of Altamira Shale in my backyard, which could be seen as a sort of "practice"). The shale that I get are usually very hard and compact, as seems to not crack very easily with the materials I have. I don't have a real chisel, but I makeshift them (nail, screws, and screwdrivers). When I use them, it seems to just dig a hole in the area where I'm striking at and creates no cracks. Does anyone who has experience with Monterey Shale know the best way to split a shale like this, preferably clean in half? (It seems that the rocks I'm trying to split are the exact same rocks found in any other part of the Monterey Formation, like Jalama Beach)

Hi everyone I recently got a large sandstone block (~20cm x 20cm x 20cm) which is like a shell deathbed (see pics). There's a layer of weathered material on the surface but underneath it's a nice piece. I was wanting to try and clean it up and do something nice with it. My ideas were to either (1) square it off and polish the block or (2) Square it off and slice it into multiple thin slabs (maybe 2-3cm thick) which could then be polished. I'm not sure if it's bad practice to slice up a fossil or not. Anyway, I was hoping someone might be able to give me some advice on what tools would be appropriate for cutting a block this size or how to go about polishing the block afterwards. Alternatively, if anyone has any other cool ideas for it I'd be keen to hear them. Any advice would be really appreciated! Cheers

As part of my fossil preparation process I have the need to reduce the size of the background rock on some specimens collected in the field. My preferred tool is a 300mm slab saw I acquired a while back made for lapidary work as this has very little vibration. Normally if I use it to cut agate or similar rock I use the cheap home brand baby oil, works a treat, good for the hands and no smell after. On the test piece I did with the softer stone the oil permeated into the rock base and the fossil and cleaning in detergent straight after only got the surface clean. I doubt the baby oil will harm the fossils but suspect it will prevent permanent gluing of damaged material and leaves and oil stain that I do not want. I tried a second piece and painted the surface with paraloid to seal, but the cut edges still stain. So currently I drain the coolant from the saws sump and replace with water cut the fossils and then drain the water from the sump as the water will cause the diamond blade to rust. The question - does anyone know of a coolant that can be used that will not seep into the softer fossils / rock and will not rust the diamond blade? Mike D'Arcy

Hi guys, I found this and felt I should share and see what you think: Ancient Hand Axe? First, I was struck by the 'cutting edge', which seems used, and has radiating shock marks from the edge, inward. There also seems to be debris in the cutting area, one piece contains 2 small, thin inset hairs, light brown in color, which I've bagged. The ergonomics are amazing. The mass of the stone fits neatly in your hand, while there appear to be wear marks where your index finger and thumb might go. Also, when held in that manner, the cutting edge is parallel to your cutting surface.

What do you guys use for cutting down matrices that are err rock hard? I've thought of a tile saw but unless a lot of money is spent then the depth of the cut is really small, 25mm/1in. Would an angle grinder with a concrete blade work? Thanks John