W. M. Foote — Shower of Meteoric Stones, Arizona. 451 



Olivine also occurs frequently in less perfect crystals asso- 

 ciated with the enstatite, but segregation is rather character- 

 istic of it in this stone. 



The diallage in mass is a brownish color. In section it has 

 in some places a very slight pinkish tinge, but is usually color- 

 less. It occurs in grains with few crystal boundaries and in 

 large crystals. One large crystal measured approximately 

 2 , 5x2 mra . It also occurs twinned or intergrown with the en- 

 statite and in some of the chondrnles it is twinned with the 

 enstatite. There are somelongish prisms with fibrous structure 

 and small extinction angle that are also monoclinic pyroxene. 



Fig. 16. 



Fig. 16. 



Sharp octahedrons of spinel in quartz. 

 Lower nicol in place. 



x 30 diameters. 



The most interesting feature observed was a patch of 

 spinels set in quartz. Of ten sections examined, these minerals 

 were found in only one. They shade in color from clear and 

 rather light ruby-red to ruby-brown. The darker are shining 

 black by reflected light, and are probably chromite. On the 

 light side of the patch the crystals are red by reflected light, 

 and are therefore a ruby- or chrome-spinel (fig. 16). They 

 occur in sharp octahedrons and are the most perfectly crys- 

 tallized mineral in the stone. They are identified by color, 

 crystal form, reflection, and position. The crystals are set in 

 semi-crystalline quartz and the patch is edged with quartz 

 that is slightly coarser. The granules of quartz are irreg- 

 ular in shape, often interlocking, and show wavy extinc- 

 tion. No figure was obtained beyond an indistinct dot which 



