Natural nickel-iron alloys have been found in several places on the earth's surface. In addition to alloys containing a low percentage of nickel (about 3%), there are others which contain much higher percentages of nickel (about 70%). To alloys of the latter group the name awaruite is now generally given and it may include josephinite, souesite, and other alloys possessing high nickel content so long as they belong to the same phase and possess identical crystal-structures.

It is of interest to the mineralogist to know whether these alloys conform to the structure of nickel-iron alloys prepared in the laboratory and whether they fit into the accepted phase diagram of the nickel-iron system. It is of interest also to the physicist and the metallurgist to obtain information concerning these natural alloys, because some nickel-iron alloys made in the laboratory are difficult to prepare in a state of true equilibrium. Data derived from the study of the natural alloys may help to throw light upon the structure of these artificial alloys.