Hello Tom and List, Yes, lab testing will probably be the only sure method to classify a meteorite unambiguously. My NWA 984 (LL4) slice has lots of easily visible FeNi metal specks, my Saint-Severin (LL6) has lots of FeNi specks (large and small), my Parnallee (LL3.6) is choke-full of metallic iron. Same thing with my Tenham (L6) or my Suizhou (L6).
So "high iron" and "low iron" does not primarily refer to the visible amount of nickel iron in the matrix. Table 3.3 in D.W. Sears (1978) The Nature and Origin of Meteorites (Adam Hilger Ltd, Bristol), p. 62 has some interesting details: Principal minerals in chondritic meteorites (wt%) for types 5 and 6: Olivine H => 33-37 / Pyroxene => 23-27 / Kamacite (FeNi) => 15-17 Olivine L => 45-49 / Pyroxene => 21-25 / Kamacite (FeNi) => 06-08 Olivine LL => 56-60 / Pyroxene => 14-18 / Kamacite (FeNi) => 01-02 In words: The amount of olivine increases, the amount of pyroxene decreases as you go from H => L => LL. But: The total amount of the low-nickel kamacite decreases from H => L => LL as more and more iron is "oxidized" that is: needed for the silicates. Best wishes, Bernd ______________________________________________ Meteorite-list mailing list [EMAIL PROTECTED] http://www.pairlist.net/mailman/listinfo/meteorite-list
