GarethGP Posted May 6, 2022 Share Posted May 6, 2022 (edited) So let me preface this by saying I'm a hypochondriac. A hypochondriac who loves fossils. To my dismay a few months back I discovered that some fossils can be slightly hot and despite assurances from the lovely people here that my pterosaur (Alcione Elainus) radius from the phosphate beds in Morocco was almost certainly safe, I bought a cheap Geiger counter to do a completely unscientific experiment to test some of my fossils for radioactivity. These are all measured in microsieverts/hour: Normal background for where I live: Range after 1 hour: 0.10-0.17 Average: 0.11 Bag of No-sodium salt: Range: 0.15-0.21 Average: 0.18 Alcione Elainus radius from phosphate beds in Morocco: Range: 0.18-0.35 Average: 0.26 Partial oreodont skull from Nebraska: Range: 0.14-0.16 Average: 0.15 Partial mastodon tooth from Florida: Range: 0.13-0.17 Average: 0.14 Partial carcharodontosaurus tooth Kem Kem, Morocco: 0.12-0.15 Average: 0.13 So it looks like the phosphate bed fossil is somewhat radioactive but nothing overly dramatic if I'm reading that correctly? Anyway, I plan on testing my other fossils and adding to this list out of curiosity! Edited May 6, 2022 by GarethGP 1 Link to comment Share on other sites More sharing options...
Wrangellian Posted May 14, 2022 Share Posted May 14, 2022 Interesting... Where do you get a cheap Geiger counter? Seems like it would be fun to play with. I've got a mineral/rock collection too and I'm curious what sort of readings I'd get on those. Link to comment Share on other sites More sharing options...
FranzBernhard Posted May 14, 2022 Share Posted May 14, 2022 (edited) 2 hours ago, Wrangellian said: Where do you get a cheap Geiger counter? There are many cheap Geiger counters out there (< 100 $). Problem with the cheap ones is, they have only a very small counting tube and are therefore not very sensitive (that means, low number of clicks at any given dose rate). Note, that @GarethGP did a hour long background reading. You may also look into "attachments" or apps for smartphones. @GarethGP, you may also try some chunks of granite! Franz Bernhard Edited May 14, 2022 by FranzBernhard 2 Link to comment Share on other sites More sharing options...
joaoarguello3 Posted June 23, 2022 Share Posted June 23, 2022 I had already heard that some minerals can be radioactive and that you have to be careful (I'm starting to collect minerals so that's good to know) but I had never heard that fossils can be. A question. What is radioactive is the fossil or the matrix piece that surrounds it? Link to comment Share on other sites More sharing options...
jpc Posted June 23, 2022 Share Posted June 23, 2022 These numbers are all interesting, but we also need to know what is considered as a worrisome level. If it is 5.0 then these numbers are all pretty safe, but if the danger line is .25, then..... Link to comment Share on other sites More sharing options...
FranzBernhard Posted June 23, 2022 Share Posted June 23, 2022 (edited) 25 minutes ago, jpc said: If it is 5.0 then these numbers are all pretty safe, but if the danger line is .25, then..... In principle, there is no safe or danger line. There are many, many factors contributing to risk. For example, two meters away from a 100 g piece of uraninite, you are back at background level. Carrying this piece in your pocket for a prolonged time, well... Radon buildup from this specimen? That´s a completely different story. Inhaling dust from that specimen? Yet another story... In summary, radiation exposure from natural radioactive minerals is rarely a danger. Incorporation is - directly or via the radon route. I find the measurement of sodium-free table salt very interesting. Well above background - and you are eating it! Specimens are only slightly higher - and you are not eating it. Conclusio? For some context, I find this helpful: Radiation sources and doses (link to EPA page) @GarethGP´s background dose rate (0.11 microsievert per hour) fits quite well into the data given there. Franz Bernhard Edited June 23, 2022 by FranzBernhard 1 Link to comment Share on other sites More sharing options...
siteseer Posted June 23, 2022 Share Posted June 23, 2022 I would do a search on this site using terms like "Geiger," "radioactive," radioactivity," and "background" because this topic has come up a few times in the time I've been a member. Link to comment Share on other sites More sharing options...
doushantuo Posted June 23, 2022 Share Posted June 23, 2022 (edited) https://doi.org/10.1016/j.chemosphere.2021.131444 Paywalled,so the PDF below is NOT the article itsel Radioactive fossils_ The uranium anomaly and its paleobiological implications - ScienceDirect.pdf Edited June 23, 2022 by doushantuo Link to comment Share on other sites More sharing options...
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