NO. 12 I>RU.M MOINTAINS METEORITE HENDERSON AM) IM-KKV 5 



CHEMICAL COMPOSITIOX (3F HRLM MOUNTAINS METKORITE 



A slice about three-eighths of an inch thick was polished and etched 

 to develop the structure of the iron and reveal any inclusions. The 

 sample used in the analysis was selected by cutting out all inclusions 

 or unusual structural features so as to r)l)tain a characteristic sani])le 

 of the meteorite. 



Table 2. — CotuPoiition of Drum Mouutalns iiwlcuritc 

 E. P. Henderson, analyst 



Fresh Oxiilc 



meteorite scalr<i 



Fe 90.70 Not determined 



Ni 8.59 5.42 



Co 0.58 0.51 



P trace Not determined 



S none Not determined 



Insol o.oi Not determined 



H:0 5.26 



99.88 



Sp.g.. 7.857- 



Mol. ratio= ... , ^ =10.47. 

 Ni + Co 



The Drum Mountains iron is a medium octahedritc, with hands 

 averaging about i mm. in width but with occasional wider or nar- 

 rower bands. The octahedral structure is highly devdopi'd. though 

 somewhat irregular. 



Taenite is abundant, with many thickened or wedge-shaped lamellae 

 having darkened cores due to incomplete transformation. .\ numbt-r 

 of Reichenbach lamellae up to _' or 3 cm. in k-ngth are noticeable. A 

 few nodular troilitc inclusions were observed and also a mnul)er of 

 small irregular inclusions. Schreibersite appears in irregular bodies 

 of various shapes, some of considerable size, but no rhabdites or 

 fme phosphide {^articles were observed. .Although the analysis ,>ihows 

 no sulfur and only traces of phosphorus, the .Namjile chosen for 

 analysis being carefully selected to avoid them, both troilite and 

 schreibersite are fairly abundant in the meteorites. 



Plessitc fields are numerous and show a great variety of structure. 

 Some very light fields are composed of a reticulated pattern of kama- 

 cite grains with droplets of taenite along grain boundaries. In some 

 fields the scattered taenite particles are imperfectly .sphcroidized. In 

 contrast with these "light" types are many "dense" fields composed 



