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ZielkeNightsky
Carpal Tunnel
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Reged: 10/01/06

Loc: Denmark
Accretion to the collection - what a glorious day new
      #6320666 - 01/18/14 02:37 PM

If you lookup the definitions for “accretion” in a dictionary, one definition will be:

((astronomy) the formation of a celestial object by the effect of gravity pulling together surrounding objects and gases)


This can translate into:
((meteorites) the formation of a celestial collection by the effect of a thrive to explore, pulling together surrounding objects of our origin)



The later was the case today. For some time I’ve been looking for some irons to add to the collection and today the first new specimens arrived.

The first specimen is a nice Seymchan that probably won’t stay to long in the collection. But for now I’ll study and enjoying it.


Full size image here


Full size images here

more to come

Edited by ZielkeNightsky (01/18/14 02:38 PM)


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ZielkeNightsky
Carpal Tunnel
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Reged: 10/01/06

Loc: Denmark
Re: Accretion to the collection - what a glorious day new [Re: ZielkeNightsky]
      #6321803 - 01/19/14 09:04 AM

Here's a couple of pics of an oddly shaped Campo. A new member in the collection.


Better image here


Better image here

stay tuned....


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Dave MModerator
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Reged: 08/03/04

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Re: Accretion to the collection - what a glorious day new [Re: ZielkeNightsky]
      #6321899 - 01/19/14 10:21 AM

Nice specimens..

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ZielkeNightsky
Carpal Tunnel
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Reged: 10/01/06

Loc: Denmark
Re: Accretion to the collection - what a glorious day new [Re: ZielkeNightsky]
      #6322109 - 01/19/14 12:35 PM

A couple of small Henbury was added. Here is some images of the small etched slice.

The colour is not faithful, because here I used some monochromatic light to bring out the widmanstätten patterns.


Much better picture here


Much better picture here

The pictures is taken on black piece of glass and if you examine the reflected image, you will notice a bright rim around the widmanstätten patterns. After some experimentation with the light angels (must be within a few degrees) I got the details of these crystals out. I'm not sure what's them rim is called, anyone?


Much better picture here

Stay tuned.....


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ZielkeNightsky
Carpal Tunnel
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Reged: 10/01/06

Loc: Denmark
Re: Accretion to the collection - what a glorious day new [Re: ZielkeNightsky]
      #6322146 - 01/19/14 12:55 PM

And the other Henbury, just 4.2 grams


Much better picture

Stay tuned


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rfinney
sage
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Reged: 01/17/07

Loc: Austin, TX
Re: Accretion to the collection - what a glorious day new [Re: ZielkeNightsky]
      #6322275 - 01/19/14 02:06 PM


Hello Lars:

Great stuff - especially the green crystal in the Seymchan. The photo is a keeper!

I have lots of Henbury individuals but I think your photo is the first etched specimen I have seen. Which makes me wonder why don't we seen more etched Henburys since they seem to be plentiful?

I have a few with strange shapes and a couple picked up by the Meteorite Men on their TV show - but nothing etched.

Appreciate the posting...

- RF


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ZielkeNightsky
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Reged: 10/01/06

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Re: Accretion to the collection - what a glorious day new [Re: rfinney]
      #6322317 - 01/19/14 02:20 PM

Thanks for the nice comments.

Regarding etched Henbury. I have another one that don't shows the widmanstätten patterns. It make me wonders is the one below should be re-polished and etched again?

I think I've shown it before, but here it is from the stock.



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ZielkeNightsky
Carpal Tunnel
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Reged: 10/01/06

Loc: Denmark
Re: Accretion to the collection - what a glorious day new [Re: ZielkeNightsky]
      #6322342 - 01/19/14 02:33 PM

The couple of irons I've unpacked is Sikhote-Alin. Two very different samples in regards to the surface finish.

Does anyone have comments on the difference?.

Here's some pics.


Much better picture


Much better picture

The larger of the two


Much better picture


Much better picture

Edited by ZielkeNightsky (01/19/14 02:38 PM)


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peter scherff
sage


Reged: 07/11/06

Re: Accretion to the collection - what a glorious day new [Re: ZielkeNightsky]
      #6322354 - 01/19/14 02:42 PM

Hi Lars,
The last photo that you posted looks more like a Campo del Cielo than a Sikhote-Alin. THe meteorite appears to have been highly oxidized then tumbled. Perhaps some one mislabeled it?

Thanks,

Peter


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ZielkeNightsky
Carpal Tunnel
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Reged: 10/01/06

Loc: Denmark
Re: Accretion to the collection - what a glorious day new [Re: peter scherff]
      #6324768 - 01/20/14 06:44 PM

Hi Peter

I did some investigations about the origin. I traced it back to a dealer in Tucson, Arizona (which of course I don't know). There seems to no mislabelling.

Then I compared it to my Campo's and another not so smooth Sikhote-Alin, I'll say it feels more like a Sikhote.

So I decided to photograph the Sikhote-Alins together so the light setup is the same.

Here's the result.


Here's a few pictures of another Sikhote with absolutely excellent provenance
Pic 1

Pic 2

This one is more like the odd Sikhote.


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contrailmaker
Pooh-Bah


Reged: 01/02/09

Re: Accretion to the collection - what a glorious day new [Re: ZielkeNightsky]
      #6325322 - 01/21/14 12:02 AM

Nice! Thanks for the great pictures.

CM


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Paul G
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Re: Accretion to the collection - what a glorious day new [Re: ZielkeNightsky]
      #6325592 - 01/21/14 06:59 AM

Beautiful specimens, beautiful pictures. Would like to see something in the pic like a cm cube to give it scale.

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ZielkeNightsky
Carpal Tunnel
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Reged: 10/01/06

Loc: Denmark
Re: Accretion to the collection - what a glorious day new [Re: ZielkeNightsky]
      #6326786 - 01/21/14 07:02 PM

Thanks Gus - I'm not so fund of using my scale cube. It's shiny polished surface shows dust to easy and is almost impossible to hold clean. But I do use it.

Here a couple Mundrabilla from the package


Much better image


Much better image

The next specimen is flat and to my surprise it displayed the most beautiful colours, almost glowing, under macro studio lamps.


Much better image


Much better image

Stay tuned.....

Edited by ZielkeNightsky (01/21/14 07:04 PM)


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hfjacinto
I think he's got it!
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Reged: 01/12/09

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Re: Accretion to the collection - what a glorious day new [Re: ZielkeNightsky]
      #6327032 - 01/21/14 08:56 PM

Beautiful pictures

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Glassthrower
Vendor - Galactic Stone & Ironworks
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Re: Accretion to the collection - what a glorious day new [Re: hfjacinto]
      #6327242 - 01/21/14 10:24 PM

Nice Seymchan. That green crystal makes it a keeper.

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lee14
super member


Reged: 12/19/09

Re: Accretion to the collection - what a glorious day new [Re: ZielkeNightsky]
      #6328329 - 01/22/14 12:57 PM

The difference between your two Sikhotes is simply the amount of time they passed through the atmosphere as the individuals you now have. The smooth specimen with the nice regmaglypts and dark fusion crust, separated from the main mass higher in the atmosphere, allowing more time for ablation to produce the cavities and the surface to smooth over. The piece that admittedly resembles a Campo is often referred to as 'shrapnel', it was produced closer to the ground, and had less time to form the smoothed, regmaglypted surface generally identified with Sikhotes. Also, because it lacked a fusion crust, the surface was more prone to corrosion after it landed, yielding a more Campo-like appearance.

Lee


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ZielkeNightsky
Carpal Tunnel
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Reged: 10/01/06

Loc: Denmark
Re: Accretion to the collection - what a glorious day [Re: lee14]
      #6328368 - 01/22/14 01:13 PM

Thanks for the comments. Good information about the Sikhotes Lee.

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lee14
super member


Reged: 12/19/09

Re: Accretion to the collection - what a glorious day new [Re: ZielkeNightsky]
      #6328862 - 01/22/14 04:53 PM

Hi Lars,

I think the reason that the Henbury lacks a Widmanstatten pattern is due to extreme shock and/or heating. I sometimes see the same surface appearance when I cut and etch a Canyon Diablo. It will grind flat and smooth, but no matter how long it remains in the etching solution, the only result is that fine grained surface that looks very much like your Henbury. Sometimes bands of taenite are visible and remain bright after etching. Your piece has what looks like curved lines of bright material. This could be taenite compressed from shock deformation, and the curvature would seem to point to extreme stress from shock as well. A nice piece!

Lee


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peter scherff
sage


Reged: 07/11/06

Re: Accretion to the collection - what a glorious day new [Re: ZielkeNightsky]
      #6328900 - 01/22/14 05:06 PM Attachment (13 downloads)

Hi Lee,
When Lars first posted the photos of his Sikhote-Alin samples I was expecting to see a typical “shrapnel” piece as I scrolled down. I was surprised to see a relatively featureless iron meteorite that appears to have been in a rock tumbler. The “shrapnel” samples that I have seen look as if they were torn apart. They have jagged edges, twisted shapes and striations. Lars’ anomalous sample displays none of these features. While it may very well be a Sikhote-Alin meteorite I think the only way to prove it would be to cut it and etch it. I have attached a photo of a typical Sikhote-Alin “shrapnel” sample.
Thanks,
Peter


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lee14
super member


Reged: 12/19/09

Re: Accretion to the collection - what a glorious day new [Re: peter scherff]
      #6329030 - 01/22/14 06:08 PM

Hi Peter,

Absolutely, it does lack most of the typical characteristics of the shrapnel pieces we're familiar with. The only real feature is that sharp edge on the 'bottom'. To me, it looks like the piece has been wire brushed. That tends to leave the high spots bright, and the deeper pits unaffected. I think that tumbling would leave a smoother, more uniform surface. Of course that would depend on the medium used, a large grade of abrasive would leave the surface much as we see on Lars' piece. I have similar examples of shrapnel to the one in your image, and also more smoothed specimens. I think the appearance depends both on their location on the main mass before it exploded, and the height above the ground. You're right about destructive analysis such as etching being the only way to be sure. A Sikhote of that size shouldn't show any pattern at all, while a Campo may or may not. One thing that leads me to believe it is a Sikhote is that it came with a specimen that is undeniably a Sikhote-Alin from the same dealer, but of course that's not really proof.

Lee


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