Chemical préparation of a goniatite

[Manticocerasman]

It has been a while since I’ve posted some goniatites. The expansion of the quarry where I look for them is nearing to the end, and most of the good layers are gone.

but sometimes we still find some neat specimens.

this one was found a month ago.

I used potassium hydroxide for the prepp of this one.

The chemical reaction worked realy well on this specimen. 
 

Manticoceras sp.

Late Devonian, Frasnian

Belgium.

 

[Ludwigia]

Excellent! That substance often does a great job as long as one has the patience to let it do its work. The Swiss collectors love to use it and achieve excellent results with it.

[pachy-pleuro-whatnot-odon]

Indeed! Beautiful result! 

 

3 minutes ago, Ludwigia said:

Excellent! That substance often does a great job as long as one has the patience to let it do its work. The Swiss collectors love to use it and achieve excellent results with it.

 

What base material/matrix would you use it on?

[Ludwigia]

2 minutes ago, pachy-pleuro-whatnot-odon said:

Indeed! Beautiful result! 

 

 

What base material/matrix would you use it on?

Marl.

[Manticocerasman]

Just now, Ludwigia said:

Marl.

The chemicals afect clay based sediments like shists and marls. But it has no effect on limestone and calcite. So it was perfect for this one. The goniatite was in calciteon a limestone bank and coverd with shists.

[Tidgy's Dad]

Nice result! 

[Jeffrey P]

Very fine looking specimen! Congrats. 

[Everhardus]

Lovely, good job.

[minnbuckeye]

Great technique!!! Does anyone know if this would work on ammonites from the Fox Hills Formation??

[jpc]

1 hour ago, minnbuckeye said:

Great technique!!! Does anyone know if this would work on ammonites from the Fox Hills Formation??

I doubt it based on the comments above.  The FH concretions are pretty limey.  

[Gramps]

On 5/28/2022 at 3:35 AM, Manticocerasman said:

It has been a while since I’ve posted some goniatites. The expansion of the quarry where I look for them is nearing to the end, and most of the good layers are gone.

but sometimes we still find some neat specimens.

this one was found a month ago.

I used potassium hydroxide for the prepp of this one.

The chemical reaction worked realy well on this specimen. 
 

Manticoceras sp.

Late Devonian, Frasnian

Belgium.

 

Beautiful results. Do you just sprinkle on the dry flake, or do you add any type of liquid? Thanks.

[Manticocerasman]

10 hours ago, Gramps said:

Beautiful results. Do you just sprinkle on the dry flake, or do you add any type of liquid? Thanks.

You have to make the fossil wet for it to work. Potassium hydroxide reacts to water.

Also be realy careful in what tipe of  recipient you use for the prep, the reaction gives of a lot of heat!

[FranzBernhard]

11 hours ago, Gramps said:

Do you just sprinkle on the dry flake, or do you add any type of liquid?

Most important:

Safety, safety, safety! While not really toxic, KOH is highly, really highly, caustic and nasty. One spit in our eye - eyesight gone.

Franz Bernhard

[Gramps]

7 hours ago, FranzBernhard said:

Most important:

Safety, safety, safety! While not really toxic, KOH is highly, really highly, caustic and nasty. One spit in our eye - eyesight gone.

Franz Bernhard

Yes, chemical goggles, appropriate gloves, and careful hygiene are essential when working with caustics.

[Gramps]

7 hours ago, Manticocerasman said:

You have to make the fossil wet for it to work. Potassium hydroxide reacts to water.

Also be realy careful in what tipe of  recipient you use for the prep, the reaction gives of a lot of heat!

To make sure I understand: The fossil is wet when the flakes are applied, but the fossil is not actually immersed in water--is that correct? Do you periodically dampen the fossil as the reaction takes place? Finally, how do you neutralize when finished? Thanks, and sorry for so many questions.

[Manticocerasman]

21 minutes ago, Gramps said:

To make sure I understand: The fossil is wet when the flakes are applied, but the fossil is not actually immersed in water--is that correct? Do you periodically dampen the fossil as the reaction takes place? Finally, how do you neutralize when finished? Thanks, and sorry for so many questions.

indeed, the fossil is wet but not immersed, if needed I sprinkle a bit of water on it later on Is the whole lot is drying up.

afterwards it needs do be rinsed extensively. I let it in a bucket with water and I refresh the water after a day, this during a few days.

I also add a little vinegar to the water after a few rinces to neutralise the last remains of the Potassium hydroxide.

It is pssible that after a few week the fossil is getting a white patina, then I repeat the procces in the bucket of water a few times.

 

And like @FranzBernhard said, be realy careful, it is  realy nasty stuff.

[Gramps]

On 11/24/2022 at 8:33 AM, Manticocerasman said:

indeed, the fossil is wet but not immersed, if needed I sprinkle a bit of water on it later on Is the whole lot is drying up.

afterwards it needs do be rinsed extensively. I let it in a bucket with water and I refresh the water after a day, this during a few days.

I also add a little vinegar to the water after a few rinces to neutralise the last remains of the Potassium hydroxide.

It is pssible that after a few week the fossil is getting a white patina, then I repeat the procces in the bucket of water a few times.

 

And like @FranzBernhard said, be realy careful, it is  realy nasty stuff.

Thanks so much for the great information.