METEORITES OF NORTH AMERICA. 



189 



cases so regular and the colors so light that it was at first thought such might be in part plagioclase feldspars. The 

 forms are, however, those of augite; they lack the pellucidity of feldspars, and, moreover, sections of the mineral show- 

 ing no twinning bands give extinctions as high as 39°. There is, therefore, apparently no doubt of their augite nature. 



The most striking features of the stone are its extremely irregular, almost amorphous areas. These seem in a 

 general way to resemble the amorphous chondri described by Tschermak from the meteorite of Grosnaja. They pre- 

 sent, however, certain features which suggest quite a different origin. * * * 



The chemical composition of the stone is shown in the analyses given below, as made in the laboratory of the 

 department by Dr. Peter Fireman. By treatment with solution of the double salt of mercuric ammonium chloride, 

 after the method of Carl Friedheim, there was obtained: 



Metallic portion 3. 04 



Nonmetallic portion, including troilite and chromite 96. 96 



100 



The metallic portion yielded: 



Fe 

 85.04 



Ni 

 11.93 



Co 

 2.79 



Cu 

 0.24 =100 



• The silicate portion was digested with hydrochloric acid and sodium carbonate solution after the usual method. 



The soluble and insoluble portions then yielded results as below, deducting those constituents present in combination 



as troilite, chromite, or as free carbon. 



Soluble 

 silicate. 



SiO, , - 32.91 



AL.O, 2.73 



FeO 34. 74 



MnO 94 



NiO and CoO 1. 39 



CaO 6. 43 



MgO 19-39 



K 2 11 



70 



Insoluble 

 silicate. 



53.79 



6.97 



3.50 



Na,0. 



4.33 



31.33 



.34 



.63 



.22 



99.56 



100. 69 



From these analyses the total chemical composition was calculated as follows: 



Fe 2. 59' 



Ni 36 



Co OS 



Cu 01 



Si0 2 33. 57 



ALO, 3. 24 



Cr,0, 



. 80 



FeO 26. 22 



FeS 4. 76 



MnO 68 



NiO and CoO 1. 01 



CaO 5. 45 



MgO 19. 74 



K 2 14 



Na 2 62 



C (Graphite) 36 



H,Oatll0° 16 



Metallic portion 

 = 3.04 per cent. 



Stony portion 

 = 96.96 per cent. 



99.79 

 Mineralogical composition: 



Metal 3. 04 



Troilite 4. 76 



Chromite 1. 17 



Graphite 36 



Soluble silicate (chrysolite in part) 72. 60 



Insoluble silicate (enstatite and augite in part) 18. 07 



100. 00 



Specific gravity, 3.78 (Tassin.) 



