Plate 7 



1. Pine River, Wisconsin. This iron, to be described by E. P. Henderson and the writer, 

 might be provisionally designated as an atypical coarsest octahedrite with accessory silicates. 

 The photograph shows a sparing development of very fine Neumann lines. The irregular 

 group of inclusions (upper left) consists of schreibersite (ring shaped) and taenite (V-shaped). 

 The black spots are silicate; the black lines along the grain boundary are oxide. Light 

 picral; X 60. 



2. Cape York, Greenland; medium octahedrite; Xi-Co 8.47 or 8.72 percent. Part of a 

 wide kamacite band with a profusion of Neumann lines. Irregular lamellae of taenite, 

 darkened because of supersaturation with respect to kamacite, along the boundary of a 

 large grain. Picral 100 seconds; X 30. 



3. Casas Grandes, New Mexico; medium octahedrite; Ni-Co 8.20 percent. Fine, 

 broad, and very broad Neumann lines. The unusual breadth in one set is due to the sec- 

 tion's having been made at an acute angle with the twinning planes of the bands. Picral 

 60 seconds; X 60. U. S. National Museum. 



4. Nelson County, Kentucky; coarsest octahedrite; Ni-Co 7.12 percent (Henderson, 

 in Henderson and Perry, 1943). \'ery broad Neumann lines similar to those in figure 3, 

 at higher magnification. The microstructure of this iron is generally hexahedral, although 

 on large surfaces wide octahedral bands are apparent. Picral 60 seconds; X 150. 



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