150 RE-EXAMINATION OF AMERICAN MINERALS. 



45. SCHREIBERSITE (OP PATERA). 



This meteroic mineral occurs in the American meteorites in 

 more abundance than has usually been supposed, as was fully 

 shown in a communication made to the American Association 

 for the Advancement of Science, in April, 1854; and as that 

 memoir will be published in full in the American Journal of 

 Science and Arts, nothing farther than the mere statement 

 of the analysis of this mineral is here given. G-.=7.017. 



12 3 



Iron 57.22 56.04 56.53 



Nickel 25.82 26.43 28.02 



Cobalt 32 .41 .28 



Copper... ...trace not est. 



Phosphorus 13.92 14.86 



Silica 1.62] 



Alumina 1.63 1 n . .. . , 



Lime trace not est. \ ™t estimated. 



Chlorine 13J 



100.66 99.69 



Nos. 1 and 2 were separated mechanically from the meteoric 

 iron ; No. 3 chemically. The silica, alumina, and lime were 

 almost entirely absent from No. 3 ; and in the other specimen 

 it is due to a siliceous mineral that I have found attached in 

 small particles to the schreibersite, and of which I have pre- 

 served one or two small specimens. The formula of schreiber- 

 site I consider to be JSTi 2 Fe 4 P. 



Per cent. 



Phosphorus, 1 atom 15.47 



Nickel, 2 •• 29.17 



Iron, 4 •• 55.36 



Further particulars of this mineral will be found in the paper 

 already referred to. 



46. Protosulphuret op Iron. 



This sulphuret is the one found in the meteoric irons of this 

 country. The specimen examined came from Tennessee ; its 

 specific gravity is 4.75. Its composition is different from that 

 of magnetic pyrites, although some authors consider the mag- 

 netic pyrites a protosulphuret, an inference not sustained by 

 analysis. The mineral in question afforded me 



Iron 62.38 Copper trace 



Sulphur 35.67 Silica 56 



Nickel 32 Lime 08 



