118 Whitfield and Merrill — Fayette County Meteorite. 



structure of chalcedony and still show, here and there, occa- 

 sional small areas giving the characteristic polarization colors of 

 olivine and enstatite. On examining the walls of the vein, areas 

 were observed where the gray and yellowish enstatites and 

 olivines retained their normal properties at the distance of one 

 or two millimeters, but at contact with the black vein matter 

 were reduced to the colorless non-polarizing condition of the 

 enclosures. 



The black matter of the vein when viewed in strong re- 

 flected light shows a dull bronze luster, less brilliant than that 

 of the pyrrhotite particles which it encloses. The thinnest 

 portions of the slide when examined with a power of 175 

 diameters show a brownish amorphous base through which are 

 scattered abundant irregular dust-like particles and flecks of a 

 perfectly black opaque material, the nature of which it is im- 

 possible to ascertain by the microscope alone. 



The structure of the vein is shown in figure 3 in which 



3 the finely dotted portions represent the 



\ ; -v-^^ . j black amorphous vein matter with 



{ / vo j^ . */ bronzy luster, the entirely black area, the 



A^^'oH-V/ blebs of metal and pyrrhotite, and the 



j*^t .y^°^'^ irregularly rounded, clear or partly 



mmc 



m 



gfp^f clouded area, the colorless silicates. 



£ 



;, %^~ From the study of these veins as above 



^sA^y^A-A described, we are inclined to consider 



^'•A*f 2 <$£"&-■ ^ ne c °l° r l ess particles as olivine and en- 

 ^ c ' ■? ^,Jzis^ f statite residuals which have been de- 

 J_ ^'S~\^~7~'~ prived of their normal optical proper- 



y^Y o / ^cz? : ^s" ties by the forces active in forming the 

 "- — ■ . -^o>' £||| d/^ vein. What the exact character of the 

 V"'^ 4' ; * V*1r" hlack and amorphous material maybe, 

 *g'C? still remains a matter of conjecture. It 

 __r^ is imacted upon by acids and when tested 



Portion of vein highly mag- with a needle point it breaks up readily 

 mfied - into earthy fragments which are not at- 



tracted by the magnet. 



Mr. Howell informs us that the stone in his possession shows 

 three of these veins, the largest exposure of any one on a bro- 

 ken surface being about four inches. The width and general 

 character of all, he states, appears to be uniform throughout, 

 though this can be ascertained definitely only by breaking the 

 stone.* 



* In structure these veins seem to only remotely resemble those described by 

 Tschermak (Site, der Kais. Akad. der Wiss., lxxxv. 1, p. 204), in the Mocs meteor- 

 ite and which, it will be remembered, he argued indicated an elevation of tempe- 

 rature since the consolidation of the stone, such as aided by reducing vapors and 

 gases fused the iron and pyrrhotite without affecting the silicates. He describes 

 the brown and black 'Fullmasse" of the vein as an admixture of the same sub- 



