N0.1J77. CASAS GRANDES METEORITE-TASSIN. 73 



ahuosl iniin.Mliately into solution, the remainder was exceedinglj^ 

 ivfractoiN . 1Mh' refractory material was washed free from acid, dried, 

 and exaniined under the lens. It was found that the g-rains were all 

 coated with a colorless, transparent silicate. This was saved and 

 other portions of the iron, amounting- in all to 500 grams, were treateil 

 with dilute hydrochloric acid to secure more^ phosphide, and. if 

 possible, more of the siliceous mineral for identification. 



The phosphide thus secured when examined under the glass showed 

 no evidences of crystalline form, and consisted entirely of small folia 

 and grains, strongly magnetic, and very brittle, having a specific 

 graviV of 7.1"23 at 20- C, and gave on analysis: 



For cent. 



Phosphorus l'^- 00 



Iron - '^-t-eS 



Nickel 20.11 



99.80 

 The schreibersite occurs fairly evenly distributed over the mass in 

 fine, hair-like lines and thin plates. It freciuently parallels the taenite 

 lamella?, and not uncommonly occurs as minute blebs and filaments on, 

 and pro'bablv grading into, the taenite. The more common occur- 

 rence is as fine, hair-like lines and thin plates occurring in the nickel- 

 poor iron and between the nickel-poor and nickel-rich iron. The 

 arrano-ement agrees with the general structure of the iron, and is so 

 simila" to the taenite bands that it may readily be mistaken for them. 

 No nodules of schreibersite are known to occur, and only occasionally 

 are the bands sufiiciently distinct to show in a photograph of an etched 

 surface as they do in the print of the cube. (Plate IV.) 



TAENITE. 

 With considerable difficulty 1.56 grams of thin taenite lamella were 

 collected and submitted to an analysis, with the following results: 



Per cent. 



Iron --82.90 



Nickel-Cobalt 16. 64 



0. 04 



Copper 



Phosphorus - "• "^ 



99.77 



This gives the following ratio for Fe and (NiCo): 



Fe : (Ni, Co) =14.80 : 2.82=7 : l=Fe., (Ni, Co). 

 The accepted formula for taenite being FegNi. 



CARBON. 

 All the carbonaceous residues were collected and examined under 

 the glass for cliftonite without success. The carbon was found to be 



