[meteorite-list] Isotropic glass in NWA 2986 Shergottite

From: STARSANDSCOPES at aol.com <STARSANDSCOPES_at_meteoritecentral.com>
Date: Wed, 12 Mar 2008 09:40:28 EDT
Message-ID: <d37.271d8064.3509374c_at_aol.com>

Hi List, Just a quick question and an observation.

Jim Strope has provided me a thin section sample of NWA 2986 Shergottite to
image. I have never seen such clear glass in a meteorite. There are
"Windows" where it is clear and completely isotropic with no color change in cross
polarized light rotation. I thought I was looking at just more epoxy at first.

I used a wave plate the draw out even the slightest difference between the
glass in the stage and the glass in the meteorite and there are still spots
that are largely indistinguishable from the glass slide. (I look for slight
dirty spots and examine in incident light to make sure of what I am looking at.)

When I read the info on this meteorite, I figured I would see some melt but
this was unexpected. Is "window clear" glass a frequent occurrence in
Martian samples?

Any one with interest in Shergottites should check this one out! Jim has a
nice write up on it at his site.


http://www.catchafallingstar.com

Thanks, Tom




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Received on Wed 12 Mar 2008 09:40:28 AM PDT