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Howdy! I found dozens of crinoid stems recently and most of them seem to have a thin layer of matrix attached. They were found in limestone, but I don't even know what mineral they've been fossilized in...calcite? Would I be able to remove the matrix with sandpaper and perhaps even polish them? Would sanding them remove visible segmentations? All help is appreciated, thank you.

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.

Some of you may have noticed my flat polished fossils and fossil rocks. A few of you have some of them in their hands, e.g. @ricardo, @taj, @Monica, @fifbrindacier, @marguy I lost access to the cutting, grinding and polishing facility recently. No great loss, but I still have some small specimens that I want to have polished. What to do? I tried a low-cost, low-effort approach, using things I already have. 1. Cutting: I tried to cut some small specimens with an angle grinder. Well, it worked, more or less. Not the best option, don´t to it. Better would be a tile saw. They are cheap, far less than $100. But this is nothing for an apartment, I think. Getting a somewhat flat surface is the biggest problem of this low-cost approach. But see below. Everything else is done on my usual desk! 2. Coarse grinding: No grinding machine here. I usually ground things flat on a diamond disk, followed by hand grinding with loose 600 and 1200 SiC (silicon carbide) grit. But I know, that limestone can be ground rather quickly by hand with SiC. Being on a low budget, what SiC should I buy? I bought SiC grit 400 (1 kg Euro 10.80,-) and SiC grit 1200 (0.5 kg Euro 14,40,-) from an Austrian supply house. What grinding plate should I use? Usually, steel plates are used. I don´ have any. But I have some glazed tiles. I was really surprised how well this worked. The SiC seems to be of very good quality and very "aggressive". A grinding time of to up to 10 minutes was enough to remove even bad scars from cutting with the angle grinder. Based on this experience, I tried to grind a small Favosites specimen without prior cutting. Worked very well, I got a flat surface of several cm2 within 10 minutes. 3. Fine grinding: I used the same tile, cleaned it thoroughly, as well as the specimens (running warm water, brush). Only 2-3 minutes necessary to grind with 1200 SiC. Grinding worked well, but specimens had some fine scratches. I am not sure if this comes from outbreaks of the tile or if the SiC has some coarse grains admixed. Will try the bottom of a stainless stell pot instead of the tile. Seems a good option, but you should not be allergic to nickel... 4. Polishing: I have usually done this on a rotating felt disk, it took only about 1 minute for small specimens and up to 10-15 minutes for quite large specimens. Some years ago, I used a piece of jeans fabric for polishing a small piece of jet by hand - worked well. I scaled it somewhat up. Used the leg of a jeans, put a tile for some stability in it. I purchased Alumina for polishing from the same supplier (0.25 kg Euro 18.00,-). It works really well, but it takes some time, about 10 minutes for small specimens, about 20 minutes or even more for somewhat larger specimens. And don´t forget to clean your specimens after fine grinding! 5. Result: Quality of polished slabs is as good as usual (except some small scratches, not visible to the naked eye), but it takes much longer and large specimens would be a real pain. 6. Costs: No hardware bought. Purchased amounts of grinding and polishing medium will last for at least 100 specimens. So costs are less then 0.5 Euro per specimen. Summing up: If you like to make a few small (< 5 cm) polished specimens of carbonate rocks (with fossils or not) or also e.g. jet, you can do this easily by hand on your desk with things you may already have at home. You need to buy some grinding and polishing medium (see above), though. And you need a somewhat flat surface to beginn with. Either naturally or a saw cut of some kind. First row: Coarse grinding with 400 SiC on tile. Second row: Fine grinding with 1200 SiC on tile. Third row: Polishing with alumina on jeans leg. Fourth row: Final results. To the right the specimens polished during the last two days (besides all my other commitments). Franz Bernhard

I have 1kg of rough Burmese amber stones ready to polish but I'm a little stumped as to where to start. I've polished Dominican pieces before using a dremel and wet sandpaper with success, but this stuff is older and much harder. In addition to the thin rough skin on these pieces, a lot have rock (or some combination of amber/earth) running through them making it difficult to figure out the plan of attack in regard to finding inclusions and getting a nice shine. Anyone here have experience with this?

I stubbled on a few small pieces of ammolite while out fishing. I have searched the internet and this forum for information and have come up with several different ways to clean and polish ammolite. However I have not been able to find a detailed process from start to finish to get ammolite looking it’s best. I know there are different qualities of ammolite and some require little to no work but mine needs some work to get it to look good without getting it wet. I have tried sanding for quite a while up to 600 grit paper. That’s the finest I could find but now have found up to 3000. Should I just keep going with the sanding? Is there polishing or buffing to do after the sanding? Is there an epoxy to put on after to keep the wet look? Any information would help and I thank you in advance. I just want to do it right the first time so that I don’t wreck it or have to go back and try to strip off something I put on.

Greetings from Central PA. I'm a total noob when it comes to fossil prep. Today I have a flattish piece, about 10" across and 1" thick. It from a large outcrop of wavy laminations that I believe are from a Keyser Formation stromatoporoid. It's pretty weathered and too hard to tell if pillars are present. So I'd like to try to grind/polish one edge. I have a good collection of metal and woodworking sanders and grinders available but nothing specifically designed for rocks. So my QUESTION IS.... is there a reasonable way to grind/polish the edge of this sample to look for stromatoporoid pillars? I'm just guessing that false negatives are common doing this sort of thing. so I thought I'd seek expert advice before I just make up some hatchet job only to get iffy results. Thanks

I recently got a new job, and to make things even better, my job is at a company who processes and places floors and walls in stone, mostly marble. This opened a few opportunities for me , having access to a huge amount of polishing and cutting tools, so this week I gave it a try: I took 2 of my Goniatites that weren't of top quality, or to hard to prep. and today the helped me to cut the fossils and polish them. The fossils turned out really well here are my first 2 polished Manticoceras sp. from the Frasnian layers of Lompret in Belgium: before polishing them: after cutting and polishing: top goniatite: Bottom Goniatite: both of them: And a question for the moderators: the fossils have been cut and polished today, but were found earlier this year, are they valid entries for FOTM since al the cleaning , cutting and polishing was done now? Thx Kevin

I bagged a couple of Nautilus while down at Lyme Regis recently. The one on the left will be a reverse prepper and still has its shell on which is a joy to see. The other is a polish job, I have a vague idea at how to do it, although I’d appreciate if anybody could give me a rundown or step by step guide on how to get it gleeming, as it’s not something I want to go in blind like I usually do. I’d appreciate any advice. Thanks.

I had to listen to a couple lectures for a school assignment which ended up totaling over 2 hours of straight listening. I cannot just sit and do nothing while I listen so I decided to do a little fossil prep. I have had this piece of what is commonly called "chunkosaurus". Chunkosaurus is a chunk of dinosaur bone that has no defining features and many times doesn't have a location attached to said specimen for us to assign it to a species or genus and so is almost practically useless to scientific endeavors. But I saw a future for this little piece so I downloaded my lectures into my phone and grabbed my stack of various sandpaper grits. I started with the opposite side looking like this. First up was some 380 grit paper to get rid of the obvious saw marks the seller I bought it from had left. Here is right after I got done with the 380 paper. Most of the saw marks except for the absolute deepest ones were gone and a little shine was showing up. I then moved onto a intermediate grit around 500 I can't tell for sure as it was old and faded on the back but I could tell the approximate grit from feeling it. This paper promptly fell apart but I got the results out of it I wanted. I then moved up to a 1200 grit then 1500 and finally 2000. I forgot to take pictures as I was getting excited to see it start to gain a mirror finish. My lectures had drawn to a close so here is my final product. Please forgive my photography, my camera is acting wonky.

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

HI there, I recently found a Petoskey Stone among others on the same tiny (12 foot) beach in Mid/Upper Michigan, as I have for years in the same location. Only...this one's different. I can't seem to polish it down entirely by hand OR with a dremel. It has a lot of beveled structure still compared to others I've seen, and it just feels HARD. There also seem to be tiny crystal bits in some places. Can Pestoskey Stones (limestone as I understand it) harden into Travertine or Marble and retain their distinct pattern and shape?

Hello, New to this forum. I recently have developed an interest in fossil inclusions in amber. After buying a number of prepared pieces, I decided I would like to try my hand at polishing some of my own. I found myself the owner of several hundred pieces of Dominican amber with inclusions. I have been doing a wet sand, and feel like I am close, but the pieces just don't seem to be getting a nice clear transparent finish. Any tips for finishing? I attached a few photos, the piece with the winged ants is from my collection and was polished by someone else, just for contrast with the one I was working on. I have a few pieces that look like they may have rarer inclusions (one looks like an earwig), so I am hoping to perfect the technique on a few more common pieces before I try my better ones. Thank you! Nathan