stats Posted November 12, 2019 Share Posted November 12, 2019 14 minutes ago, Wrangellian said: If these have pyrite infilling, I could see the removal of the outer layer of shell or patina revealing pristine, unoxidized pyrite, which would be a rich golden color if it is copper pyrite. Not to say there isn't some brush residue as well, but has anyone tried it with something other than a copper (brass) brush, to see if there is a difference? In any case, exposing fresh pyrite to air only leads to oxidation, which is what I see happening on my specimen. I tend to avoid unnatural abraded/polished/sculpted fossils also, but it was cheap and pretty. Someday I'll get a pristine, unaltered one, but it might still need to be treated somehow to protect the pyrite. I have some Pyrite that is as golden as ever after many years. I thought that Pyrite is stable and Marcasite was unstable. Isn't Pyrite disease more correctly called Marcasite disease? Cheers, Rich Link to comment Share on other sites More sharing options...
Ludwigia Posted November 12, 2019 Share Posted November 12, 2019 4 hours ago, Wrangellian said: If these have pyrite infilling, I could see the removal of the outer layer of shell or patina revealing pristine, unoxidized pyrite, which would be a rich golden color if it is copper pyrite. Not to say there isn't some brush residue as well, but has anyone tried it with something other than a copper (brass) brush, to see if there is a difference? In any case, exposing fresh pyrite to air only leads to oxidation, which is what I see happening on my specimen. I tend to avoid unnatural abraded/polished/sculpted fossils also, but it was cheap and pretty. Someday I'll get a pristine, unaltered one, but it might still need to be treated somehow to protect the pyrite. 4 hours ago, stats said: I have some Pyrite that is as golden as ever after many years. I thought that Pyrite is stable and Marcasite was unstable. Isn't Pyrite disease more correctly called Marcasite disease? Cheers, Rich I've brushed the shell off a lot of "pyritized" ammonites from Buttenheim with a steel brush and the result is almost always a silvery gold color. You get to recognize copper-brushed ammonites from here quite quickly once you've developed an eye for them. Here's a typical P.transiens and a P.spinatum from Buttenheim. Yes, there is a lot of marcasite here, particularly in the spinatum zone, which is why I have to protect these ammonites since they are prone to disease. Some of them last for a long time, but some start getting a coating of gypsum after a short period of time. I guess it depends on the conditions under which they developed. Just for interest's sake, here is a typical "Goldschnecke" Amaltheus sp. from the Pliensbachian at another site in Baden-Wuerttemberg. 2 Greetings from the Lake of Constance. Roger http://www.steinkern.de/ Link to comment Share on other sites More sharing options...
Wrangellian Posted November 12, 2019 Share Posted November 12, 2019 You know, I decided I should take another look at my specimen since it's been a long time since I looked at it, and it turns out the while stuff is just the bits of white shell that the brush didn't get. So that answers that! It's not decaying. What threw me is I don't recall seeing that white stuff when I first bought it, I thought it had developed later. So you can scratch what I said earlier. Anyhow, I'm not so worried now, but on the other hand I'm not as impressed with it. It looks more crudely prepped to my more experienced eye than it seemed back then. Link to comment Share on other sites More sharing options...
Wrangellian Posted November 12, 2019 Share Posted November 12, 2019 5 hours ago, stats said: I have some Pyrite that is as golden as ever after many years. I thought that Pyrite is stable and Marcasite was unstable. Isn't Pyrite disease more correctly called Marcasite disease? Cheers, Rich Good question! I wouldn't know... Ive been taking the term 'pyrite disease' at face value, but you may be right. I've got various pyrite specimens that haven't changed for years, too. Link to comment Share on other sites More sharing options...
sharkdoctor Posted November 12, 2019 Share Posted November 12, 2019 Thanks for the tour! 1 Link to comment Share on other sites More sharing options...
Misha Posted November 12, 2019 Share Posted November 12, 2019 11 hours ago, stats said: I have some Pyrite that is as golden as ever after many years. I thought that Pyrite is stable and Marcasite was unstable. Isn't Pyrite disease more correctly called Marcasite disease? Cheers, Rich I think pyrite can still oxidize under sertain conditions although it is generally more stable. Here is what I found on the internet: " Pyrite will slowly oxidize in a moist environment, and release sulfuric acid that is formed during the process. Well-crystallized specimens are generally relatively stable, while pyrite formed as sedimentary concretions has a tendency to decompose quickly. " https://www.mindat.org/min-3314.html 1 Link to comment Share on other sites More sharing options...
Phevo Posted November 12, 2019 Share Posted November 12, 2019 7 hours ago, Wrangellian said: You know, I decided I should take another look at my specimen since it's been a long time since I looked at it, and it turns out the while stuff is just the bits of white shell that the brush didn't get. So that answers that! It's not decaying. What threw me is I don't recall seeing that white stuff when I first bought it, I thought it had developed later. So you can scratch what I said earlier. Anyhow, I'm not so worried now, but on the other hand I'm not as impressed with it. It looks more crudely prepped to my more experienced eye than it seemed back then. I think Ludwigia showed a very nice variety of iron brushed specimens In alot of the specimens from the site the shell is very fragile and soft, and flakes off, so brushing them is one way to make them more interresting Best regards 1 Link to comment Share on other sites More sharing options...
Mike from North Queensland Posted November 12, 2019 Share Posted November 12, 2019 Nice tour Mike Link to comment Share on other sites More sharing options...
Nimravis Posted November 12, 2019 Author Share Posted November 12, 2019 47 minutes ago, Mike from North Queensland said: Nice tour Mike Thanks Mike Link to comment Share on other sites More sharing options...
Wrangellian Posted November 13, 2019 Share Posted November 13, 2019 6 hours ago, Phevo said: I think Ludwigia showed a very nice variety of iron brushed specimens In alot of the specimens from the site the shell is very fragile and soft, and flakes off, so brushing them is one way to make them more interresting Best regards To me they're just as interesting with the shell on. If the shell is to be removed, it should be done carefully, and mine was not done so carefully! I've never been a fan of brushing - the high points always take the brunt of the brushing while the nooks and crannies are harder to access. Same thing with Elrathia kingii trilobites. You can always tell when they've been brushed. Link to comment Share on other sites More sharing options...
FossilNerd Posted November 13, 2019 Share Posted November 13, 2019 My wife would hate it if I ever step foot in that store. There goes our bank account! Thanks for the wonderful pics and tour! Excellent report as always! 1 The good thing about science is that it's true whether or not you believe in it. -Neil deGrasse Tyson Everyone you will ever meet knows something you don't. -Bill Nye (The Science Guy) Link to comment Share on other sites More sharing options...
Recommended Posts
Create an account or sign in to comment
You need to be a member in order to leave a comment
Create an account
Sign up for a new account in our community. It's easy!
Register a new accountSign in
Already have an account? Sign in here.
Sign In Now