Plate 51 



1. Hex River Mountains, South Africa; hexahedrite; Ni-Co 6.34 percent, P 0.23 per- 

 cent. Part of a band of needles and irregular bodies of schreibersite. Long parallel bands 

 of that character are found in other hexahedrites. Large rhabdite at right. Picral; X 60. 

 U. S. National Museum. 



2. Cedartown, Georgia; hexahedrite; Ni-Co 5.70 percent, P 0.30 percent. Part of a 

 long band of inclusions similar to figure 1, but of regular crystalline form. Profuse Neu- 

 mann lines. Picral and 10 minutes neutral sodium picrate; X 30. 



3. Wiley, Colorado; nickel-ri'ch ataxite; Ni-Co 12.31 percent. Part of a long schrei- 

 bersite inclusion surrounded by kamacite containing Neumann lines. The minute spindles 

 and particles of kamacite, which are profuse in this iron (pi. 19), are absent near the inclusion, 

 all the excess kamacite having been absorbed into the larger body. Another explanation 

 of the absence of kamacite spindles may have been the absorption of phosphide into 

 the schreibersite body, resulting in the absence of small phosphide particles, which else- 

 where are found inside the kamacite spindles and which might have served as nuclei 

 for the precipitation of kamacite. Picral 50 seconds; X 30. 



4. Shingle Springs, California; nickel-rich ataxite; Ni-Co 17.34 percent, P 0.34 percent. 

 A structure similar to the preceding. The schreibersite needle and the smaller schreiber- 

 site body are surrounded by kamacite. Like Wiley, this iron in general shows a profusion 

 of minute kamacite bodies, but they are sparse or absent near such inclusions. Picral 70 

 seconds; X 30. U. S. National Museum. 



171 



