Hi Alan,
I'm no expert on meteoritic iron-nickel content, but I think we need to focus your question a little bit. Perhaps it would help to consider if one could identify confidently objects made solely from meteoritic iron. If so, then one could ask whether such identification can be extended to objects that are made partly of meteoritic iron.
Sideritic meteorites are reported to have greater fractions of nickel than seen in terrestrial iron deposits. This would seem to be one distinguishing feature that might be helpful. Sideritic meteorites are also likely to contain Cobalt, while terrestrial deposits are not. There are also the "rare earth metals" of the Lanthanum series that are more likely to be present in meteorites. Based on the metallic elements known to occur in various forms of sideritic meteorites, one could build up an elemental profile that would help identify a meteoritic origin.
The real problem comes, I think, when meteoritic iron is used in combination with terrestrial iron to forge an object. Diluting and contaminating the meteoritic metals with terrestrial metals would probably make it much more difficult to identify the meteoritic elements.
Ian
|