Buying heteromorph ammonites, any red flags?

[Mochaccino]

Hello,

 

I'm considering purchasing between 3 heteromorph ammonites. I wanted to ask if they are authentic, and whether it seems like there is any restoration or carving going on. Also, if there's any one that looks to be in particularly bad condition.

 

Here is #1. Presumably Nostoceras:

 

 

 

 

 

#2, also Nostoceras, appears upside-down in matrix with turricone still embedded. Perhaps I can prep that myself?

 

 

 

 

And #3, listed as Acrioceras tabarelli:

 

 

 

Edited December 4, 2021 by Mochaccino

[Coco]

Hi,

 

Broken links. Please put your pics directly on TFF.

 

Coco

[Mochaccino]

1 hour ago, Coco said:

Hi,

 

Broken links. Please put your pics directly on TFF.

 

Coco

Oops, sorry. Edited to include photos

[caterpillar]

Indeed Nostoceras and it seems authentic

[Mochaccino]

1 hour ago, caterpillar said:

Indeed Nostoceras and it seems authentic

Thanks, any restoration or carving/sculpting you can identify? Also, it seems the turricone abruptly ends but doesn't look like it's broken off. A bit weird?

 

I edited my post because I'm considering between 3 specimens.

Edited December 4, 2021 by Mochaccino

[RJB]

All but the last one has has some serious carving.  Here is the first one I did to show.  For me, this is painfully obvious.  Ive seen a ton of these and it seems that 99% of them have been carved, fixed and repaird in some way.  This is the reason I myself gave up on trying to find one. 

 

RB

[Mochaccino]

18 minutes ago, RJB said:

All but the last one has has some serious carving.  Here is the first one I did to show.  For me, this is painfully obvious.  Ive seen a ton of these and it seems that 99% of them have been carved, fixed and repaird in some way.  This is the reason I myself gave up on trying to find one. 

 

RB

 

Oh wow I see, thank you so much for your input. My untrained eye couldn't tell and I'm very glad I asked here. Is this the norm because these Nostoceras species so rarely preserved? Perhaps it has something to do with those found in Madagascar, as I've heard Madagascar prohibits the export of raw, unpolished fossils and so people are forced to tamper with them as "works of art"? I noticed that the vast majority of Cleoniceras for instance from that region are all heavily polished.

 

Either way this is such a shame, these are such exotic fossils and I would like to have one in its naturally fossilized state. At least I take it the last Acrioceras appears raw and untampered?

 

 

Edited December 4, 2021 by Mochaccino

[caterpillar]

1 hour ago, RJB said:

All but the last one has has some serious carving

 

I don't agree.

I just think the preparation is bad. Some ribs have been cleared a little too deep.

We can see that the interior of the ribs is lighter while the top which has not been touched is the same color as the rest of the fossil.

But that's just my opinion

 

 

 

 

[FranzBernhard]

3 hours ago, RJB said:

serious carving.

 

1 hour ago, caterpillar said:

have been cleared a little too deep.

Not much difference, technically .

Franz Bernhard

[caterpillar]

For me, there is a difference between a carved fossil and a poorly cleared fossil.

A carved fossil is a piece of rock that has been given the appearance of a fossil.

A poorly cleared fossil is an existing fossil for which poor preparation gives it the appearance of a sculpture.

In the first case, we have a creation.

In the other case, a degradation

[RJB]

21 hours ago, caterpillar said:

don't agree.

I just think the preparation is bad. Some ribs have been cleared a little too deep.

We can see that the interior of the ribs is lighter while the top which has not been touched is the same color as the rest of the fossil.

But that's just my opinion

This is done in 2 part epoxy but purty much the same thing,  Its easy to do even though I had to work in some little small 'horns' into this one.  You dont have to agree but I would bet everything I own that I know exactly how they carve the bad areas on those ammos and I alsos know exactly what tool they use. 

 

 

[glu]

I do also believe it is carved with an engraver, Nostoceras are often incomplete on the inner worls. Many good speciments were often available in the last few years, but now it seems that they are very hard to get, I wish I had got some when those were easy to obtain...

[caterpillar]

It doesn't matter how this ammonite got released. What I mean is that at the base it was genuine and the preparation was too strong. This is not the sculpted matrix

I have already cleared a lot of these Nostoceras and I know the problem

Here one I have prep

 

[glu]

@caterpillar yes I understood your point, you are saying that they got too deep with the Dremel and so they eroded the real ammonite.

I still anyway agree with RJB that there wasn't an ammonite under there, and those sections in ammonite #1 are carved. I also prepared a medium batch of them for a fossil company in NE Italy last year: all of them had some not preserved parts

 

 

[FranzBernhard]

Are these essentially molds (steinkerns) or is there any actual shell left?

 

2 hours ago, glu said:

all of them had some not preserved parts

Are these the parts where the matrix was in direct contact with the inner mold (steinkern), without any separation layer? If so, the separation line between carving and overprepping, well, is not quite there...

Franz Bernhard

[Notidanodon]

Looks more carved in those areas than badly prepped to me