Authentic Seymchan?

[met.rod]

Hello all,
could you please help me verify that what I bought on the weekend is authentic?
For me it looks very real, even though I cannot see the Widmanstätt figures/structure and Neumann lines very clearly, which are a perfect proof of authenticity.
Looking forward for your replies.
Thanks a lot everyone ;-)

 

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[Red-Coat]

Welcome to Tnet.

Nice specimen. It looks good from where I sit, has typical structure for Seymchan, and I see no obvious red flags.

Main Group Pallasites are both difficult and expensive to convincingly fake. I know of only one 'convincing' example (Shirokovsky), which MetSoc preferred to categorise as a "pseudometeorite", shying away from calling it a fraud. I prefer the word "fake" (ie man-made).

I wouldn't worry that you can't see obvious Widmanstatten figures or Neumann lines. They aren't always visible and, especially for pallasites, cut slices are often prepared with such a high degree of polish that these features are obscured. it then needs a degree of chemical etching to enhance them, which would destroy the display value of the high polish.

 

[met.rod]

Thanks a lot, @Red-Coat.
The seller states that they have acid-prepped the meteorite with very high effort to make the Widmanstatten figures & lines visible, covering all the olivines one-by-one to protect them. I feel there are some smaller well-visible figures on the top and in the center, in the first photo.
Will post more photos as soon I hold this beauty in my hands.

 

[galenrog]

The central problem with preparing this piece for display is polishing vs etching. The same dilute nitric acid that make Widmanstatten patterns pop out so beautifully will also adversely affect olivine and other nonmetallic structures on the polished surface.

Were I the professional preparing this piece, if I had no input from buyer or owner, I would prefer the appearance of the polished surface, to include the highly polished olivine inclusions over Widmanstatten pattern.

Twenty years ago, I may have had the skills to find a suitable compromise. Alas, no longer.

Still, you posted an absolutely wonderful specimen.

Time for more coffee.

 

[met.rod]

Thanks so much for your comment, @galenrog .
For me being a newbie, the preppers of my Seymchan have done a brilliant job, doing both polishing as well as etching. I also love it a lot, and I hope next generations will still be able to enjoy it.

@Red-Coat, I was a bit afraid when I started to study about the Shirokovsky pseudo meteorite. It really looks similar to Brahin or Sericho, but mine surely doesn't look like a Shirokovsky ;-)

On eBay I have seen many "Sericho meteorites" from China which don't convince me at all ;=0

 

[galenrog]

Thanks so much for your comment, @galenrog .
For me being a newbie, the preppers of my Seymchan have done a brilliant job, doing both polishing as well as etching. I also love it a lot, and I hope next generations will still be able to enjoy it.

@Red-Coat, I was a bit afraid when I started to study about the Shirokovsky pseudo meteorite. It really looks similar to Brahin or Sericho, but mine surely doesn't look like a Shirokovsky ;-)

On eBay I have seen many "Sericho meteorites" from China which don't convince me at all ;=0

Thank you.

Years ago, when I did a lot of lapidary, I also cut specimens for others. More than a few thousand were presented as meteorites. Several hundred of these were polished, followed by a dilute nitric acid etching. Only a handful appeared to have patterns similar to meteorites. The owners of those pieces were advised to present them to certified organizations for authentication. Only two or three people ever got back to me after authentication was accomplished.

A lot was learned about identifying what was clearly not a meteorite. I do not, however, pretend to know as much as Red-Coat.

Time for more coffee.

 

[met.rod]

Had promised you some photos and here even is a video for you.
Photos:

Video for you on Youtube.

I am quite a bit concerned about the lower left corner though, I hope so much there is no rust / oxidation. Scared! Can you tell?


Thanks a lot to you guys already in advance.

 

[met.rod]

My professional seller clearly states there is no rust on my Seymchan, and he has never seen rust even after 10 years on any of them.

Also this Seymchan has that orange stuff on it while that seller (no, I have not bough from this seller) clearly states there is no rust - "acid prep & polishing, no rust, stable", so it should be something else. But then what is it?
https://www.ebay.de/itm/123960850139

 

[galenrog]

From my perspective, the orange color you describe is not rust, but rather polishing media which transferred to the piece, probably through improper polishing technique.

In a few cases over the decades I played with rocks, I failed to properly prepare the surface for a final polish. In two or three of those, polishing media transferred to the piece in such a way that I had to revert back to a 400 grit grind to remove it. Basically starting over.

Without personal inspection, this is my best guess.

Time for more coffee.

 

[met.rod]

Thanks you so much, @galenrog . I really fell in love with my beautiful piece, and am so happy it's healthy.

So I will just keep it in my air-tight display case together with some bit of silica gel, so we can enjoy it long-term.

I've purchased a mirror to be put in the back of the case, to see the reverse and to make the olivines shine in bright color.

Have a beautiful weekend everyone.