452 II r . M. Foote — Shower of Meteoric Stones, Arizona. 



had no effect on a quartz wedge. The quartz is sufficiently 

 identified, however, by its low refraction, double-refraction 

 showing colors up to white, and by the characteristic habit 

 of the grains. 



These patches of spinel and quartz are analogous to the 

 patches of olivine and glass previously described. The two 

 minerals should probably be regarded as secondary minerals 

 formed by a reaction (perhaps influenced by Cr 2 3 ) between 

 the olivine and anorthite or a glass near to anorthite in com- 

 position. 



Chromite was found in three sections. It occurs associated 

 with the metallic minerals. It is black by reflected light and 

 dull red by transmitted light. Both patches and crystals were 

 found. 



Fig. 17. 



Fig. 17. Chondrule of enstatite surrounded by native iron and 

 pyrrhotite. x 16 diameters. Nicols crossed. 



Nickel- Iron Content. 



Mr. George C Davis made the few chemical determinations 

 of the aerolite which limited time permitted. The specific 

 gravity was found to be 3 - 22. One hundred grams, freed 

 from crust, were finely powdered and treated repeatedly with 

 the electro-magnet. The metallic portion was washed with 

 alcohol to remove the silicates, but the separation was incom- 

 plete and the silicates Anally constituted about 25 per cent of 

 the magnetic concentrates. The material for analysis was 

 taken from twelve individuals. 



