[meteorite-list] Isotropic glass in NWA 2986 Shergottite

[STARSANDSCOPES 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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