116 BULLETIN [)i, UNITED STATES NATIONAL MUSEUM. 



Two portions of this constituent, each weighing 10 grams, were 

 taken for analysis, with the following results : 



Per cent. 



Iron (Fe) 82.520 



Nickel (Ni) 14.044 



Cobalt (Co) .949 



Copper. (Cu) .104 



Sulphur (S) .288 



Silica (SiOj) .80S 



Aluminum (Al) .410 



Carbon (C) .465 



Phosphorus (P) .390 



Chlorine (CI) Trace. 



99.978 



The tsenite occurs in very thin, brittle, tin-white lamellae, with a 

 specific gravity of 7 at 20.1° C, and has the following composition: 



Per cent. 



Iron (Fe) 63.99 



Nickel (Ni) 35.98 



Cobalt (Co) .10 



Copper (Cu) Trace. 



Phosphorus (P) .04 



100. 11 



The material is strongly magnetic, but does not possess polarity. 



Schreibersite occurs fairly abundantly, approximating 1.35 per cent 

 of the mass by measurement and 1.95 per cent by analysis. It occurs 

 bounding the olivine areas and occasionally penetrating or contained 

 in them. The more common occurrence is, however, as blebs, veins, 

 or filaments in the nickel-iron constituent. The mineral has a brilliant 

 tin-white color, is strongly magnetic, possessing polarity, and in one 

 instance an as undoubtedly crystallized, but, unfortunately, the speci- 

 men was so brittle that it fell to pieces on attempting to measure it. 



An analysis gave the following : 



Per cent. 



Iron 64. 990 



Nickel 18.905 



Cobalt .105 



Phosphorus 15. 700 



Copper Trace. 



99. 700 



Troilite occurs commonly associated with the black specular mate- 

 rial lining the cavities containing the olivine in the nickel-iron con- 

 stituent. It varies in its dimensions from a coating a line in thickness 

 to masses 2 or more millimeters thick by 10 millimeters in length. 

 Grains and flakes of troilite are occasionally contained in masses of 



