The crystal structure of meteoric iron as determined by X-ray analysis

The well-known "Widmanstätten" figures, obtained by etching the polished surface of meteoric iron, suggest the occurrence of two types of crystal structure in alloys of the nickel-iron series. Those figures, easily obtained when the meteorite contains more than 7 percent. and less than about 14 per cent. of nickel, owe their existence to the presence of two constituents. One of these, "taenite," contains a higher percentage of nickel than the other, "kamacite," and is much less easily attacked by etching reagents.