540 



Description and Analysis of a large mass of 



[Nov, 



Brazilian specimen that of a ches- 

 nut, but with thick flakes of oxide 

 below. 



The glossy surfaces of his block 

 are not smooth, but slightly in- 

 dented all over, as if hammered 

 with a rather large round-headed 

 hammer. 



The Siberian specimen, Pallas 

 thinks, was originally covered with 

 a rough ferruginous (oxided ?) crust 

 which had been broken off to obtain 

 pieces of it. 



The brown colour of the sur- 

 face of the block is merely a very 

 thin coat of rust, for the slightest 

 scratch with a knife produces a 

 bright metallic streak. — Pallas' 

 Voyage. 



ores than anything I can liken it to ; 

 but they are rarely or never honey- 

 combed. Small water-worn speci- 

 mens of this last named mineral 

 sometimes are so, and one of these 

 magnified, or a huge lump of dark 

 coloured ferruginous Kunkur, gives 

 one the best mineralogical notion of 

 the appearance of our large speci- 

 men. If seen in the bed of a tor- 

 rent it would indeed have been 

 thought a mass of water-worn iron- 

 stone, if no accidental friction had 

 shown its bright metallic streak, 

 which is apparent upon the slight- 

 est scratch ; except at the few sco- 

 riaceous parts. 



When closely examined there are 

 seen to be parts which are evident- 

 ly more scoriaceous and cellular in 

 appearance than others. In a very 

 few places minute fragments or 

 patches of a yellow and reddish or 

 orange-coloured felspar or sand- 

 stone-like mineral, with a slight 

 gold-coloured lustre in a strong 

 light, are found imbedded and. evi- 

 dently fused in, with the scoriaceous 

 part ; sometimes having a very little 

 green glassy mineral like broken 

 bottle glass fused around or close 

 to them ; both are highly brittle, 

 and in such minute quantities, and 

 so imbedded in the mass that it is 

 only by careful poring over it with 

 a magnifier that they are detected ; 

 and it is impossible to do more 

 than to obtain minute blowpipe 

 fragments, from which it however 

 appears clearly that the glass is 

 Olivine, being just fusible on the 

 edges, and first discolouring, and 

 then so far disintegrating as to fall 

 to pieces when touched, after two 

 or three days' digestion in muriatic 

 acid; which then gives the reac- 

 tion of peroxide of iron.* The 



* The olivine of meteoric stones does not gelatinise like that of basalt and other 

 volcanic specimens, (See Vol. XIII. of Journal, p. 884, Examination of the Kandeish 

 Aerolite.) Specimens are too small and scarce for us to ascertain what this is owing to. 



