[meteorite-list] porous chondrite - crystals in matrix

[Phil Morgan]

Hello again,
Let me ask a more direct question.

Admittedly, the pictures aren't very interesting at first glance.  But, with 
a closer look, I'm hoping you can actually pick out the small crystals 
sticking out of the matrix.  I've re-read Norton's artice in the May 04 
issue of Meteorite magazine and don't find any mention of this phenomenon. 
Is this type of think in the matrix of most/all chondrites, just harder to 
pick out of most unless in thin section?

I don't believe this piece is very weathered.  I've seen very weathered NWA 
material where the metal has completely oxidized and the silicates are 
breaking down that almost look porous.  I don't believe that to be the case 
here.

Would these crystals have formed after-the-fact, or accreted along with the 
chondrules?  What would they be?  Some are more transparent and some seem 
quite black.  I'm very much a newbie at the minerals.

Thanks again,
Phil

----- Original Message ----- 
From: "Phil Morgan" <pkmorgan at ctcweb.net>
To: <meteorite-list at meteoritecentral.com>
Sent: Monday, September 11, 2006 7:37 PM
Subject: [meteorite-list] porous chondrite


> Hello everyone,
> Great thread on Neumann lines!
>
> The list has generally been a bit quiet so thought I'd share something and 
> solicite opinions.
>
> The links below (reasonable quality hopefully) are of an NWA at 20x.  The 
> matrix is quite porous and of a sandy texture.  Anyone know of anything 
> classified that might look similar?  Any observations or comments?
>
> broken exterior:
> http://i25.photobucket.com/albums/c57/pkmorgan/porous%20OC/exterior.jpg
>
> cut surface:
> http://i25.photobucket.com/albums/c57/pkmorgan/porous%20OC/cut.jpg
>
> largest chondrule:
> http://i25.photobucket.com/albums/c57/pkmorgan/porous%20OC/chondrule.jpg
>
> Thanks for viewing and regards!
> Phil
>
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