[AdmSmith]

• There has been a controversy about the origin of Bronze Age irons that could be either meteoritic or smelted irons.

• A geochemical approach using Fe:Co:Ni analyses, permits to differentiate terrestrial from extraterrestrial irons.

• Meteoritic irons, Bronze Age iron artifacts, ancient terrestrial irons and lateritic ores enable to validate this approach.

• Modern irons and iron ores are shown to exhibit a different relationship in a Fe:Co:Ni array.

• Iron from the Bronze Age are meteoritic, invalidating speculations about precocious smelting during the Bronze Age

https://www.sciencedirect.com/science/article/pii/S0305440317301322

[AdmSmith]

If you have a chunk of metal or a rock that contains metal and the metal contains >4% nickel (Ni), then it is probably a meteorite. If the metal contains >0.02% chromium (Cr) or manganese (Mn), then it is not a meteorite, however.

If the metal contains <4% nickel, then the metal chunk or rock is not a meteorite.

If you have a rock that contains between 1.0 and 1.8% nickel (whole-rock analysis), whether or not it appears to contain metal, then the rock might be a meteorite.

If you have a rock that does NOT contain metal and has a low concentration of nickel (<1% = <10000 ppm), it could still be a rare type of meteorite, an achondrite. (About 5% of stony meteorites are achondrites. The probability is exceedingly small, however, because nearly all (guesstimate: >99.999%) Earth rocks have the same properties - no iron-nickel metal and low concentrations of nickel (<0.3%)

http://meteorites.wustl.edu/id/metal4.htm

[RegulatorCountry]

I guess the engine block of the 455 in my old GMC motorhome is from outer space then, whoda thunk lol?