Mallet — Stony Meteorite from Coon Butte, Arizona. 351 



more rarely, porphyritic, structures. Except where stained 

 bv a recent oxidation of the ferruginous constituents, both 

 minerals are colorless or but slightly gray. 



In addition to the mineral above described is a completely 

 colorless isotropic substance occurring, as a rule, with no crystal 

 outlines, but rather filling interspaces as would an interstitial 

 glass. It is sometimes quite free from enclosures or, again, 

 includes numerous silicate grannies and opaque metallic par- 

 ticles. Rarely does it show anything suggestive of cleavage 



Section showing supposed maskelynite at a. 



(see fig. 3 a). Excepting in its lack of crystallographic out- 

 lines, the mineral is similar in all respects, as far as appearance 

 goes, to the maskelynite of the Shergotty (India) meteorite, 

 and such I shall have to assume it to be. It is altogether too 

 small in amount to permit a satisfactory chemical determina- 

 tion, though with more material a micro-chemical test might 

 be made which would go a long way towards settling the prob- 

 lem. 



The chonclritic structure of the stone is not strongly marked, 

 and the individual chondrules are themselves almost invariably 

 of a fragmental nature. The one shown in fig. 4 is the most 

 perfect exhibited in any of the slides. The structure, as a 

 whole, is not unlike that of the Ness County, Kansas, stone, 

 and hence, if we follow Brezina, would be placed in the group 

 of intermediate chondrites, brecciated (Cib). As, however, I 

 have examined this stone only in thin sections, none of which 



