The Amateur Paleontologist Posted May 17, 2020 Share Posted May 17, 2020 Hey everyone, hope you're all doing well! From what I've read, small shark/fish teeth can be occasionally encountered by dissolving samples of chalk/limestone in acid. I read Jeppsson et al's 1999 paper on using buffered acetic acid to extract phosphatic fossils (in my case shark teeth), but the method outlined is not that simple and requires access to certain laboratory equipment I don't really have access to right at the moment... All I have is some cheap white vinegar, and some trays and tins I've got some samples of chalk from the Late Cretaceous of Møns Klint, a fossil site in Denmark with relatively diverse fish and shark fauna. Here's the thing - would it be OK to put the samples of chalk in white vinegar (acetic acid)? If it is, I've just got some questions -- Should I dilute the vinegar? And if so, by how much? How long should I leave the chalk in the vinegar? Any suggestions and ideas would be much appreciated, I'd love to find some little fish and shark teeth. Christian Opalised fossils are the best: a wonderful mix between paleontology and mineralogy! Q. Where do dinosaurs study? A. At Khaan Academy!... My ResearchGate profile Link to comment Share on other sites More sharing options...
hadrosauridae Posted May 17, 2020 Share Posted May 17, 2020 if you have a spare piece of chalk, why not put in to test? I wouldnt dilute household vinegar, its only 5% strength when new. What lab equipment do you need to soak a rock in vinegar? 2 "There is no shortage of fossils. There is only a shortage of paleontologists to study them." - Larry Martin Link to comment Share on other sites More sharing options...
The Amateur Paleontologist Posted May 18, 2020 Author Share Posted May 18, 2020 8 hours ago, hadrosauridae said: What lab equipment do you need to soak a rock in vinegar? Quoting one of the papers I read: Quote THE NEW STANDARD TECHNIQUE Equipment. Plastic vessels with lids (a 10-liter vessel is useful for 0.5 to 2kg samples). Hose [at least 2-3 m long] Colanders, either plastic or stainless steel Hydrometer calibrated from 1.000 to 1.100 pH meter and liquids for calibrating it Sieve -- e.g., a nylon sieve with 63μm holes Acetic acid Buffer Water Taken from "The Optimal Acetate Buffered Acetic Acid Technique for Extracting Phosphatic Fossils" by Jeppsson et al. 1999. Items 4, 5 and 6 would be rather hard for me to get access to right now... Opalised fossils are the best: a wonderful mix between paleontology and mineralogy! Q. Where do dinosaurs study? A. At Khaan Academy!... My ResearchGate profile Link to comment Share on other sites More sharing options...
Ptychodus04 Posted May 18, 2020 Share Posted May 18, 2020 Leiggi et. al. 1994 calls for 1tsp. Calcium Phosphate for every 1000ml (approx. 4 cups) of 5% formic acid solution as a buffer. White vinegar is 5% acetic acid and acts similarly to formic. You want to make sure you soak in clean water as long as you soak in acid. I typically do a daily rotation, depending on the reactivity of the matrix. 1 Regards, Kris Global Paleo Services, LLC https://globalpaleoservices.com http://instagram.com/globalpaleoservices http://instagram.com/kris.howe Link to comment Share on other sites More sharing options...
Phevo Posted May 19, 2020 Share Posted May 19, 2020 With skrivekridt we in Denmark usually use a different method, "glaubersaltmetoden", were you basicly turn the matrix into mush, by creating small crystals that split the rocks (similar to the thaw freeze method, but much faster) which you then sieve afterwards to find the micros. It has worked fine for me with bryozo chalk aswell 1 Link to comment Share on other sites More sharing options...
The Amateur Paleontologist Posted May 20, 2020 Author Share Posted May 20, 2020 Thanks for the advice guys. 22 hours ago, Phevo said: With skrivekridt we in Denmark usually use a different method, "glaubersaltmetoden", were you basicly turn the matrix into mush, by creating small crystals that split the rocks (similar to the thaw freeze method, but much faster) which you then sieve afterwards to find the micros. It has worked fine for me with bryozo chalk aswell What do I need to make the Glaubersalt Method work? On 18/05/2020 at 10:30 PM, Ptychodus04 said: Leiggi et. al. 1994 calls for 1tsp. Calcium Phosphate for every 1000ml (approx. 4 cups) of 5% formic acid solution as a buffer. White vinegar is 5% acetic acid and acts similarly to formic. You want to make sure you soak in clean water as long as you soak in acid. I typically do a daily rotation, depending on the reactivity of the matrix. Alright, thanks for the information - I'll keep that in mind. Opalised fossils are the best: a wonderful mix between paleontology and mineralogy! Q. Where do dinosaurs study? A. At Khaan Academy!... My ResearchGate profile Link to comment Share on other sites More sharing options...
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