956 



PROCEEDINGS OF THE NATIONAL MUSEUM. 



VOL. XXVII. 



The largest of the .schreiber.site areas is 3 by 6 mm. along its greatest 

 diameters, and, like the troilite, it contains carbon, but unlike it, it 

 does not carry olivine. This phosphide occurs also in yerj thin 

 plates bounding the iron masses, and between them and the troilite. 

 It occasionally occurs in small grains or plates in the iron constit- 

 uent, and is then arranged in dendritic or moss-like aggregates. 

 Scliroibersite also occurs in thin plates linealh' arranged and resem- 

 bling ttenite. 



Etching the iron constituent develops a baud of bright white iron 

 next to the troilite and schreibersite areas and bounding them. This 

 alloy may be '"kamacite." but it was not possible to separate any of it 

 to determine its composition. On each side of and bounding the white 

 iron is a ver}- thin plate standing in relief, which in certain instances 



T 



.-» ' 





PHOTOMICROGRAPH OF OLIVINE IN GRAPHITIC TROILITE AREA. 



is known to be schreibersite and in others ta?nite. The mass of the 

 iron constituent is made up of a darker colored alloy, or eutectic. In 

 this eutectic is seen tine lines of a tin-white color, which are in part 

 tsenite, and which penetrate the mass in zig-zag shapes. Examined 

 under a glass the dark iron appears to be homogeneous, and to be 

 made up of minute octrahedrons arranged in line lamellae. It should 

 be here stated that the eutectic or dark iron does not contain any 

 chlorides, and the very small amount of chlorides present was noted as 

 occurring as lawrencite between the troilite and the boundary "white 

 iron" alloy. The Persimmon Creek iron may be classed as a granular 

 octahedrite containing numerous troilite and some silicate areas. 



