[meteorite-list] D'Orbigny, Unusual Angrite, Thin Section Photographs

[peterscherff at rcn.com]

Hi,

	With all this talk of Angrites; I hope that some one can help me
find a sample of Angra dos Reis for my collection.

Thanks,

Peter Scherff

-----Original Message-----
From: meteorite-list-bounces at meteoritecentral.com
[mailto:meteorite-list-bounces at meteoritecentral.com] On Behalf Of MARK
BOSTICK
Sent: Wednesday, May 11, 2005 12:33 PM
To: meteorite-list at meteoritecentral.com
Subject: [meteorite-list] D'Orbigny, Unusual Angrite,Thin Section
Photographs

Hello list,

(Forgive me for if any of the following is scientifically wrong, this is my 
observations paired with my at times limited knowledge.)

I recently received a D'Orbigny thin section.  Which I have placed several 
photographs of on my web site at the following web page.

http://www.meteoritearticles.com/coldorbigneyts.html

One the best thin sections I have. OK, move over NWA 998, it is the best.  
This is due to its prismatic augite crystals, often found twisted with 
olivine, randomly placed anorthite shards, and the many large vugs/vug 
inclusions, in the stone. Some of these are filled with olivine or glass, 
some are empty and some are hollow, meaning the show traces of the former. 
In one vug on my thin section, is a well formed specter shaped crystal 
sticking out. In my microscope it appears bright red, so perhaps it is 
olivine. Another interesting note on the crystal that it formed in a hollow 
vug. Meaning in a vug that has traces of the former minerals that once 
filled the vug. This would mean of course that it formed after whatever was 
in the vug, which is most likely olivine. This is all my amateur observation

and if anyone thinks the crystal, seen in photo 7, is not olivine, let me 
know your opinion please. Also photo 7 and photo 11, shows particle bugs 
with, under cross polars, appears brown as shown. This is what I think are 
hollow vugs, as described in a couple of papers. The former mineral thing 
again. Empty vug walls are shown in photos 7 and 8.

Opinions and thoughts welcomed,

Clear Skies,
Mark Bostick
Wichita, Kansas
http://www.meteoritearticles.com
http://www.kansasmeteoritesociety.com
http://www.imca.cc

http://stores.ebay.com/meteoritearticles


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