A Feature In Meteorite Times Magazine
by Tom Phillips and Martin Horejsi

 

Microscopic Photos of NWA 2371 H4

Even ordinary chondrites have surprises.  NWA 2371 H4.  One stone with a mass of 2950 gr.  This meteorite has the most unusual fusion crust I have seen.  I have polished a lot of slices of many types of meteorites and I always examine the polished portion of the crust.  This one seems rather unique.  It crystallized into beautiful patterns when it cooled.  I have no idea if this was caused by the way it cooled or the chemical makeup of the interior material.

 

 
NWA 2371 H4.  2950 gr. whole mass with cut and polished slice.
 
 

 
This micrograph is of the fusion crust.  It was taken in incident (reflected) cross polarized light at 1600X.  Maybe the formation of these crystals could provide some insight into the formation process of similar structured crystals found interior to some other exotic meteorites.  For example we know it was completely melted and cooled very rapidly.  Crystal growth in meteorite structure is often attributed to slow cooling!
 
 

 
This micrograph is of an unusual interior structure that resembles a micro Pallasite.  Taken at 1600X.
 

Tom Phillips can be reached by email at:

STARSANDSCOPES@aol.com