[meteorite-list] New Gebel Kamil meteorite with Schlieren bands

From: Tim Heitz <midwestmeteor_at_meteoritecentral.com>
Date: Sun, 3 Oct 2010 16:17:58 -0500
Message-ID: <78C9D7CA85B2451BB072B3B23D977C86_at_den>

Hello Bernd,

Thanks for the nice explanation.

The schlieren banding will only be seen after etching, I got it

Tim



----- Original Message -----
From: <bernd.pauli at paulinet.de>
To: <Meteorite-list at meteoritecentral.com>
Sent: Sunday, October 03, 2010 1:47 PM
Subject: [meteorite-list] New Gebel Kamil meteorite with Schlieren bands


> Hello Tim, Mirko, and List,
>
> As Mirko already pointed out, the schlieren banding will only be seen
> after etching (at least slight etching or deep-etch if you prefer that).
>
> Only then will you see these characteristic diffuse streaks (usually of
> group
> IVB ataxites - another reason why Gebel Kamil is classified as
> "ungrouped").
>
> The image that Mirko provided and one of my slices (from Mirko) clearly
> reveal those bands and patches dovetailed into each other and tapering out
> irregularly.
>
> Now, when you tilt such polished and etched slices against a light source,
> you will notice that bright and matte parts shift alternatingly: the bands
> that were bright from one perspective, now appear dull and vice versa.
>
> This oriented sheen has to do with the "alpha + gamma" structure, cooling,
> decomposition, (absence of) diffusion, crystallographic orientation, etc.
> .. too complicated (for me :-) to explain.
>
> Best "Schlieren"
> wishes,
>
> Bernd
>
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Received on Sun 03 Oct 2010 05:17:58 PM PDT