THE PIMA COUNTY METEORITE — HENDERSON AND PERRY 355 



called schreibersite, are both unknown. The results of the determi- 

 nations in both portions were used to calculate the percentage of the 

 elements present in each portion. The analysis reported for the mete- 

 orite was obtained by combining the analyses of schreibersite and 

 kamacite. 



This schreibersite is unusually high in cobalt, considerably above 

 any other analysis of this mineral found in the literature. Since the 

 analysis was made by dissolving the residue, which was insoluble in 

 hydrochloric acid, in aqua regia and dividing the solution into ali- 

 quot parts, there was no chance for any check determinations. The 

 authors have no reason, however, to question the results. The ratio 

 between FeNiCo and P is 3.02 to 1 and is consistent with the theoreti- 

 cal ratio for this mineral. The general composition of this iron is 

 in close agreement with other nickel-poor ataxites. 



The only other nickel-poor ataxite known from Arizona is the 

 Navajo iron, which is now in the Chicago Natural History Museum. 

 Unfortunately, that important specimen has never been studied, and 

 the only published information as to its composition is a short note by 

 George P. Merrill ^ in which its type was announced and a statement 

 made that the nickel content was 5.81 percent. 



The Pima County iron, though of unknown origin, will be consid- 

 ered a separate and distinct meteorite unless otherwise proved from 

 later information. 



1 Amer. Journ. Sci., ser. 5, vol. 3, p. 154, 1922. 



U. S. 60VERNMENT PRINTING OFFICE; 1949 



