Howard and Davison — Estacado Aerolite. 59 



ous inclusions. The inclusions in the enstatite are generally 

 parallel to the cleavage." He found the specific gravity to be 

 3'60. The microphotograph (fig. 4) was made between cross 

 nicol prisms, the magnification being about forty diameters. 



II 



Chemical Analysis by John M. Davison. 



The specific gravity of the Estacado aerolite is 3- 63. The 

 metallic part was separated with a magnet, and the slight 

 amount of adhering stony matter determined and deducted. 



The stony part was separated by hydrochloric acid into a 

 soluble and an insoluble portion. The insoluble portion was 

 digested with a solution of Na 2 C0 3 and the dissolved Si0 2 

 added to that dissolved by HC1. This analysis gave 



Metallic. 16-41 per cent. 



«. (Soluble in HC1... 41-09 " 



bt0ny 1 Insoluble in HC1 . 42-50 " 



100 



Analyses of these, omitting minor constituents and calcu 

 lated to 100, gave 





Metallic. 



Soluble in HC1. 



Insoluble in HC1. 



Fe. 



89-45 



Si0 2 32-00 



Si0 2 63-57 



NL 



9'99 



MsfO 32-02 



MgO 23-45 



Co 



0-56 



*FeO 31-60 



FeO 9-54 







CaO 4-38 



CaO 3-44 



100 100 100 



The stony part appears to be mainly olivine and enstatite. 

 The analysis of the entire mass gave the following percentages : 



Fe 14-68 A1 2 3-60 



Ni 1-60 Na 9 0* 2-07 



Co 0-08 K 2 G .__ 0-32 



Cu _ trace Ti0 2 found but not determined 



C found but not determined Cr„0 



ic 



2 3 



S 1-37 MnO 



P 0-15 



SiO, 35-82 100-95 



FeO 15-53 Less O for S "68 



MgO 22-74 



CaO .... 2-99 100-27 



