METEORITES OF NORTH AMERICA. 



189 



cases ao 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 



The metallic portion yielded: 



100 



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 Insoluble 



silicate. silicate. 



Si0 2 .................................................... 32. 91 53. 79 



ALA ................................................... 2.73 6.97 



FeO ................................. .................... 34. 74 3. 50 



MnO ..... ................................................ 94 ...... 



NiO and CoO ............................................ L 39 ...... 



CaO ...................................................... 6. 43 4. 33 



MgO .............................. .' ..................... 19. 39 31. 33 



K 2 ...................................................... 11 -34 



NajO .................................................... 70 .63 



H 2 O at 110 .............................................. 22 ...... 



99. 56 100. 69 



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



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.) 



