[meteorite-list] Fa and Fs values of LL meteorites

[tett]

Hello List,

Have just purchased a nice slice of a low TKW LL3.  NWA 2461.

The met bulliten lists Fayalite (mol%): 26.5±2.5
      Ferrosilite (mol%): 12.5±7


The Met Bulliten also gives an official classification of an LL3.  The 
encyclopedia of meteorites states that an LL3 should have a Fs value of 
32-40 so how can this be grouped as an LL3?  The Fa value fits.

Looking at many other LL meteorites from the Met Base I see that the 
majority have Fs values well belwo the 32-40 level.  I wonder if I am 
interpreting these incorreectly?

Any help would be gratly appreciated.

Cheers,

Mike Tettenborn
Owen Sound, Ontario