MnO / Fe2O3(T)
The ratio of manganese to iron does
not vary much within different groups of meteorites. The
MnO/Fe2O3(T) ratio (or Fe/Mn or FeO/MnO)
is not as reliable a test for meteorites as some sources
imply, although ratios of <60 are nconsistent with lunaites
and >50 are inconsistent with eucrites, for example.
See Notes, Caveats, and References