4.">d II '. M. Fpote — Shower of Meteoric Stones, Arizona. 



occur in irregular but usually rounded patches and grains, in 

 about equal amounts. The pyrrhotite occasionally shows 

 crystalline laces. Magnetite in small jet black or slightly 

 bluish black grains occurs to less extent than the other 

 metallic minerals. 



Fig. 15. 



Fig. 15. Imperfect polish showing distribution of nickel-iron. At large 

 end a chondrule encircled by minute iron grains. x 1'7 diameters. 



The principal constituent of the stone is enstatite, which 

 forms probably 50-60 per cent hy volume. It occurs in 

 prisms from l mm X "25 mm in size down to minute allotriomor- 

 phic grains. It also occurs often in chondrules with radiating 

 structure (fig. 17), and in one section a chondrule was found 

 with tangential structure, i. e. the fibers formed a regular 

 polygon. Enstatite appears to have been one of the first 

 minerals to separate and to have continued its separation until 

 the magma cooled. In mass the enstatite has often a slightly 

 greenisb color. It is colorless in section. 



Olivine and monoclinic pyroxene (diallage) make up the bal- 

 ance of the stone. Olivine occurs usually in crystals and 

 crystal grains set in a grayish glass. A group of olivine set in 

 glass will be divided from the rest of the stone often by sharp 

 demarcation as though it were an inclusion of another stone. 



