450 H. 8. Washington — Jerome Meteorite. 



crystal, surrounded by a mosaic of small grains of the same 

 mineral. There were a few monosomatic chondrules of oli- 

 vine, with approximately circular outline, but curiously and 

 irregularly hollow, the interstices between the separate patches 

 of olivine being filled with granular bronzite. Others again 

 were found with monosomatic borders and portions of the 

 interior of bronzite, containing olivine grains. 



The crystals and fragments of bronzite and olivine offer no 

 features of special interest. They are colorless, except where 

 stained by ferruginous decomposition products, and are quite 

 fresh, even the olivine showing no traces of serpentinization. 

 Each mutually encloses the other, so that they were apparently 

 crystallized at the same period. Both include small angular 

 fragments of iron. Only a few crystals and fragments, which 

 could be definitely referred to pyroxene, were observed. In 

 one case two pyroxene fragments, giving oblique extinction, 

 are enclosed in a patch of bronzite. A few grains which may 

 be referred to plagioclase were found, one of these showing 

 traces of twinning lamellae. 



Grains of nickel-iron are quite abundant. They are all small 

 and angular and irregular in outline ; and apparently generally 

 later than either the olivine or bronzite, as they are xenomor- 

 phic toward these and occupy the interstices between them, and 

 also include crystals and fragments of these minerals. At the 

 same time, as we have seen, small particles of iron are included 

 in these minerals. 



The iron has suffered greatly from oxidation, being usually 

 surrounded by yellow, or deep reddish-brown, translucent, 

 doubly refracting, matter. This is probably limonite, since it 

 answers to Pelikan's* description of limonite under the micro- 

 scope, and since the analysis shows that there is no silica, 

 above that necessary for the olivine, etc., to form a ferrous 

 silicate, as it was suggested to be by Kunz and Weinschenkf 

 in the case of the Washington, Kansas, meteorite. This fer- 

 ruginous substance has penetrated all the crevices of the mass, 

 being found in the interior of even the largest mineral grains, 

 is seen in patches throughout all the sections, and is what 

 gives the brown color to the mass. 



A careful search revealed no grains of troilite, though the 

 chemical analysis shows that about five per cent was probably 

 present originally. It has possibly been entirely decomposed. 



For the chemical analysis 25'2 grams were taken, of as fresh 

 material as was available, with no crust attached. An attempt 

 was first made on 13 grams to separate the nickel-iron by 

 means of an electro-magnet. This proved to be a matter of 



* Pelikan, Tsch. Min. Petr. Mitth., xiv, 5, 1895. 



f Kudz and Weinschenk, Tsch. Min. Pet. Mitth., xii, 180, 1891. 



