A sad day

[Ptychodus04]

It’s a sad day. Years ago, I collected a microconch and macroconch of Scaphites so. from the Late Cretaceous Arcadia Park Formation in Dallas, TX that were preserved in pyrite. I’ve collected dozens of pyritized ammonites from this particular site and all have been stable. These ammonites appeared to be stable for about 15 years until one day the pyrite decay started. I noticed it a couple days ago and soaked these specimens in iron out to try to stop the decay.

 

Alas, my attempts were unsuccessful and both specimens crumbled to powder.  

 

Beware pyrite, even if you think it’s ok…

[Fossildude19]

Ah, that stinks.  Sorry to hear it, Kris.   

[Ptychodus04]

Yah, unfortunately I don’t know how long they had been rotting away in the drawer. Can’t be too long as it was only a month or two ago when I was last in the drawer. Pyrite decay is nasty. I’m just glad I found it before the acid affected other specimens.

[FossilNerd]

 

Sorry for your loss Kris! I’ve never collected any pyritized fossils, but I hear pyrite disease is nasty stuff.  

[erose]

Argh! I haven't had it happen yet. I put lots of dissecant packs in with the pyrite specimens. Crossing my fingers.

[Tidgy's Dad]

I recently found some of my Sheppey pyrite fossils and a lovely Echioceras from Charmouth reduced to dust.

It's very sad, especially when they're your own finds and have memories from decades ago attached.

[Ptychodus04]

Yep. These were the only 2 scaphites in my collection and I happened to find the 2 sizes (male/female) only a week apart and in the same general vicinity of each other.

 

At least they went together in the end.

[Yoda]

I have recently reading a bit about pyrite decay. 

 

Aside from the obvious gold Ammonites

How do you recognise if a fossil contains pyrite ?? 

[North]

Thats very sad.

Chemistry wise, pyrite is quite unstable. Did you have them in container of some sort while inside the drawer?

[t-tree]

15 hours ago, Tidgy's Dad said:

I recently found some of my Sheppey pyrite fossils and a lovely Echioceras from Charmouth reduced to dust.

It's very sad, especially when they're your own finds and have memories from decades ago attached.

 

I collected some beautiful Charmouth pyrite ammonites that have turned to dust over the years they are more susceptible from that location 

 

John

[Ptychodus04]

6 hours ago, Yoda said:

I have recently reading a bit about pyrite decay. 

 

Aside from the obvious gold Ammonites

How do you recognise if a fossil contains pyrite ?? 

 

Often, pyrite grows on or in different fossils. It will appear gold, silver, or sometimes black on the surface. If broken, it is usually silver. If you have a hard, metallic blob on your fossil, it's probably pyrite.

 

2 hours ago, North said:

Thats very sad.

Chemistry wise, pyrite is quite unstable. Did you have them in container of some sort while inside the drawer?

 

They were in an open tray

[joaoarguello3]

I didn't know that this happened to pyritized fossils. I had planned to buy a pyritized ammonite soon, but now I'm afraid since where I live there is a lot of humidity.

[SPrice]

Sorry to hear about the loss of the scaphites and others who lost specimens to pyrite decay.

And what is the method for mitigating pyrite decay? I have some recently purchased Yorkshire Coast ammonites which are not the golden pyrite type but have pyritic layers or areas underneath the shale or limestone.  Would that also be why the matrix is so easily removed when scribing the outer skin of the nodule and about halfway in becomes hard as heck; showing golden scratch marks where the tungsten stylus scrapes along?

 

Will a somewhat thick coating of consolidant prevent the decay - CA, Paraloid, White glue/water mix coating, floor polish? Anything? Utah is very low humidity but we plan to move back east near the ocean in North Carolina in a few years.

 

Wait a minute!...I'm old...I may be a decaying fossil myself before the ammonites turn to dust. Lol.

Edited October 20, 2023 by SPrice

[fifbrindacier]

On 10/20/2023 at 5:43 PM, SPrice said:

Wait a minute!...I'm old...I may be a decaying fossil myself before the ammonites turn to dust. Lol.

Hi Toumaï, how are you ?

[minnbuckeye]

On 10/20/2023 at 10:43 AM, SPrice said:

Will a somewhat thick coating of consolidant prevent the decay - CA, Paraloid,

 

I am currently exposing fossils from a Silurian location that often have beautiful pyrite crystals attached. Your thoughts mimic mine in that a sealant should prevent the decay. Hopefully a professional opinion of this will be rendered soon!! 

[Jaybot]

No professional here, but I have heard from others that paraloid B-72 or other sorts of consolidants can seal pyrite thus preventing moisture from reacting with it.  Hopefully someone that has actually tried it can chime in.

[hemipristis]

On 10/17/2023 at 6:28 AM, Ptychodus04 said:

It’s a sad day. Years ago, I collected a microconch and macroconch of Scaphites so. from the Late Cretaceous Arcadia Park Formation in Dallas, TX that were preserved in pyrite. I’ve collected dozens of pyritized ammonites from this particular site and all have been stable. These ammonites appeared to be stable for about 15 years until one day the pyrite decay started. I noticed it a couple days ago and soaked these specimens in iron out to try to stop the decay.

 

Alas, my attempts were unsuccessful and both specimens crumbled to powder.  

 

Beware pyrite, even if you think it’s ok…

 

On 10/17/2023 at 11:07 PM, t-tree said:

 

I collected some beautiful Charmouth pyrite ammonites that have turned to dust over the years they are more susceptible from that location 

 

John

 

+1

 

The survivoring specimens are now packed in a ziplock with desiccant packets

[Ptychodus04]

On 10/27/2023 at 9:32 PM, Jaybot said:

No professional here, but I have heard from others that paraloid B-72 or other sorts of consolidants can seal pyrite thus preventing moisture from reacting with it.  Hopefully someone that has actually tried it can chime in.

These specimens were sealed with Vinac. Worked for about 15 years.

Edited October 30, 2023 by Ptychodus04

[Jaybot]

Oof, too bad.  At least now we all know not to use vinac on pyrite.  Sorry for the fossil loss Kris