OBSIDIAN BOMB FROM NEW SOUTH WALES. 119 



Mitchell, who probably found it in the interior of New South 

 Wales. Messrs. W. H. Twelvetrees, f.g.s. and W. F. Petterd, 

 C.M.z.s., 1 record a "bomb," which from their description somewhat 

 resembles the one recorded in this note, for "it is without the 

 flange or beading, which is apparently characteristic of the buttons 

 obtained on the east coast." 



My specimen from its shape etc., therefore, is also comparable 

 to those known from West Australia, but unfortunately it is not 

 perfect — one-third or more of the whole having been broken off, 

 so that more correctly speaking it is only a portion of a "bomb" 

 that is now to be macroscopically described. It is worthy of note 

 that of the two belonging to this type of bomb, and now recorded 

 from Eastern Australia and Tasmania, one should have been 

 found in Tasmania (loc. cit.), and the other in New South Wales. 

 This latter specimen, the subject of this note, is rather bright 

 looking, and not so dull as those I have examined from Western 

 Australia, although however, it strongly resembles them in every 

 other respect. 



It has a blackish, very dark bottle-green, glassy appearance, 

 particularly so at the large fracture, which shows a little fire on 

 the edge. It measures about 1 inch in diameter and J inch in 

 thickness, and might be described in general terms as sub-globose 

 in shape. There is quite an absence of concentric rings, flanges, 

 or flutings round the edges, which are very thick and rounded. 

 The whole of the surface is irregularly indented with gas pores 

 and broken globulites of varying size, and these no doubt occur 

 throughout the mass, although only a few are exposed on the big 

 fracture above referred to. Viewed under a lens, the surface has 

 much the appearance of that of many meteorites, such as for 

 instance, the Thunda meteorite from Queensland and others. The 

 specific gravity is 2-456 at 15° C, almost identically the same as 

 the one described from Tasmania, (loc. cit.) and showing it to be 

 "Obsidian" (glassy varieties of rhyolitic and trachytic rocks) and 



1 Roy. Soc, Tas., 1897, p. 42. 



