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Marlowe

strange crystals grew on my ammonite

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Marlowe

A while ago I bought this tiny gault clay ammonite preserved in pyrite and in a few months of storage next to dessicant mineral these strange white crystals have grown. -pyrite disease?5bce002f57ad6_20181022_1746091.thumb.jpg.c6748c61ff0298c9ddc06f86929b9d6a.jpg

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caldigger

Was this found in a current marine setting ( shoreline)?  It might be salts leaching out and crystallizing.

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Darktooth
57 minutes ago, Harry Pristis said:

Highly probable that it's pyrite disease.  You can find lots of suggestions on this forum for treating this condition, but my experience with these ammonites suggests that you should just chuck the specimen and never buy another pyritized fossil.

Well that's a buzz kill!:P

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Ludwigia
1 hour ago, Paciphacops said:

The crystals appear to be gypsum. The oxidation of the pyrite produces sulfuric acid, which reacts with calcium carbonate within the fossil to produce calcium sulfate. I'm no expert on pyrite disease, but the prognosis is probably not good. :(

I believe this is correct about the gypsum. Once it's sick, it'll never properly recover unfortunately.

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caldigger
27 minutes ago, Ludwigia said:

I believe this is correct about the gypsum. Once it's sick, it'll never properly recover unfortunately.

I hear if you soak it in warm chicken soup, and give it plenty of rest it tends to help with the sickness.

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Wrangellian

If only!  :wacko:

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KimTexan

I certainly wouldn’t throw it out. It is still a beautiful specimen. 

Gypsum can be very hard to remove if it is encrusting it. Some fossils I find in the Britton Formation here in Texas are coated with it.

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Darktooth
4 minutes ago, KimTexan said:

I certainly wouldn’t throw it out. It is still a beautiful specimen. 

Gypsum can be very hard to remove if it is encrusting it. Some fossils I find in the Britton Formation here in Texas are coated with it.

But you wouldn't want to keep it with other specimens as it can also damage them. If you chose to keep it, you would want to put it in an airtight container away from anything else.

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JimB88

your lucky, all the ones I collected that were pyritized (wood impressions from a coal seam) turned into white powder with no crystals (and fast too.)

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Harry Pristis
1 hour ago, Darktooth said:

But you wouldn't want to keep it with other specimens as it can also damage them. If you chose to keep it, you would want to put it in an airtight container away from anything else.

 

Darktooth is right.  Gypsum is not the problem.  The problem is the sulphuric acid.  I have a hole in a metal gondola shelf produced by a forgotten pyritized item that decomposed over a few years.  Chuck it!

 

 

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caldigger
1 hour ago, Darktooth said:

But you wouldn't want to keep it with other specimens as it can also damage them. If you chose to keep it, you would want to put it in an airtight container away from anything else.

What he is really saying is to isolate it into a sturdy package and send it off to New York c/o Darktooth. :fingerscrossed:

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Bobby Rico

I have had pyritised fossils for many years and would be really feed up it any of them got the disease. I would try and save them with ammonia vapours and then varnishing,  Pyrite rot is a problem. The decay rate varies a lot,  some specimens go straight away while I seen others in old collections from the 19th century that are still ok . Do a search on the TFF first on how to treat the rot  . I think the disease maybe triggered by the conditions that the fossil are kept in.  If you have other pyritised fossil I would treat them for the disease just to make sure . Better safe than sorry.

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Darktooth
1 hour ago, Bobby Rico said:

I have had pyritised fossils for many years and would be really feed up it any of them got the disease. I would try and save them with ammonia vapours and then varnishing, I think that is right (but do a search on the TFF first)   . I think the disease maybe triggered by the conditions that the fossil are kept in.  If you have other pyritised fossil I would treat them for the disease just to make sure . Better safe than sorry.

Moisture in the air is what triggers it.

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Bobby Rico
13 minutes ago, Darktooth said:

Moisture in the air is what triggers it.

Yeah I thought that even if you have not got damp in your house the atmospheric conditions of the area you live in could cause the rot I guess . If the op has got other specimens because he already got the rot in their collection I would try to treat them. What do you think Dave ?:dinothumb: 

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Darktooth
15 minutes ago, Bobby Rico said:

Yeah I thought that even if you have not got damp in your house the atmospheric conditions of the area you live in could cause the rot I guess . If the op has got other specimens because he already got the rot in their collection I would try to treat them. What do you think Dave ?:dinothumb: 

I think it depends on how unstable this material is. Treating might help but if the rot has already set In it may be too late.

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Bobby Rico
2 minutes ago, Darktooth said:

I think it depends on how unstable this material is. Treating might help but if the rot has already set In it may be too late.

I was thinking treat any of their pyrite fossils they have in the collection even if they have no signs of rot to be safe. I think this specimen in question is a goner sadly.  :(

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caldigger

Send your collection for "storage" to me in California...we've never experienced this thing you call moisture. ;)

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Marlowe

I'll probably just chuck it. They're unimaginably common there and I bulk-bought a few species so it's not worth treating it. Also, since posting the pictures, 10 others in the same container are encrusted in a green and yellow powder. I have moved roughly 30 to another box but I'm not optimistic. It's like the plague!

20181023_150400[1].jpg

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Marlowe

I just hope they don't get my 'baby'!:(

20181023_150451[1].jpg

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Darktooth
3 hours ago, Bobby Rico said:

I was thinking treat any of their pyrite fossils they have in the collection even if they have no signs of rot to be safe. I think this specimen in question is a goner sadly.  :(

Yes, but rot could be occurring on a microscopic level that you can't see and you can end up with the same result after treatment.  I say this from experience. I coated a couple fossils that I self collected with polyurethane or acrylic.  The premise was to keep it sealed from moisture and air. None of these fossils showed signs of rot. Some stayed fine for years some started rotting rather quickly. Anything is worth a shot but it my not be a cure all is my point. I would still keep treated specimens away from other fossils and keep your eye on them.

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Bobby Rico
23 minutes ago, Darktooth said:

Yes, but rot could be occurring on a microscopic level that you can't see and you can end up with the same result after treatment.  I say this from experience. I coated a couple fossils that I self collected with polyurethane or acrylic.  The premise was to keep it sealed from moisture and air. None of these fossils showed signs of rot. Some stayed fine for years some started rotting rather quickly. Anything is worth a shot but it my not be a cure all is my point. I would still keep treated specimens away from other fossils and keep your eye on them.

I am not in disagreement with you . But if you do the ammonia treatment first before coating does that not give you more chance that the rot will be kept away for a longer time period. :) to me it sounds like there a problem here better to try to stop it. 

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Darktooth

I had not heard of using ammonia before so I am not sure how that would work.

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