Meteorite Dagger?

[Jeff Pringle]

The answer is in the trace elements, they are the fingerprint for cosmic origin.

You can get trace elements by INAA as well as EMP, with a very small sample size.
I think in addition to a good Iridium anomaly, a blade with a percentage of meteorite would have oxygen isotopes that are skewed off the terrestrial mass fractionation line.
By looking at the Cobalt/Nickel ratio you might get some clues as well.