NO. 9 METEORITE FALL IN ARIZONA — MERRILL 3 



structure as in a feldspar. These are often so charged with a black, 

 amorphous powder as to quite obscure their real nature, and it is only 

 by analogy or surmise that one is led to believe them to be maskelynite. 1 

 A chemical investigation of the stone by Dr. J. E. Whitfield, of 

 Philadelphia, yielded the results as below : a 



Per cent 



Schreibersite o.n 



Troilite 7.56 



■Metal 4-85 



Silicates 87.48 



100.00 

 The metallic portion yielded : 



Nickel 8.68 



Cobalt 0.64 



Copper 0.29 



Iron 00-50 



100. 11 

 The silicate portion yielded : 



Silica 41-93 



Alumina 4 • 30 



Ferrous oxide 21 .85 



Lime 2.40 



Magnesia 29.11 



Soda trace 



Manganese protoxide 0.25 



Nickel oxide 0.08 



99.92 



Specific gravity at 22.6° C. 3.48. 



The stone is low in iron, though not unprecedentedly so, and high 

 in sulphur, but otherwise presents no unusual features. A total lack 

 of chlorine is to be noted, but unfortunately this element is so fre- 



1 It may be well to state here that not being satisfied with my determinations 

 of this supposed maskelynite in Coon Butte, Rich Mt, Thompson and other 

 meteoric stones, I submitted uncovered slides of the first mentioned to Dr. 

 F. E. Wright of the Carnegie Geophysical Laboratory. In these he determined 

 the index refraction of the doubtful mineral to be 1.51. According to Larsen's 

 determinations (Amer. Journ. Sci., vol. 28, 1909) on refractive indices of 

 feldspathic glasses, this would relegate it to a feldspar near oligoclase in 

 composition. 



1 This analysis is one of several made for the writer under a grant from the 

 J. Lawrence Smith fund by the National Academy of Sciences, to which 

 body he is indebted for permission to use it here. 



