while colour. It is translucent ; yields easily to the knife, though 

 not to the nail ; scratches marble, but not crystallized fluor. 

 Its specific gravity is 2.698. When breathed upon, it yields 

 an argillaceous odour distinctly. Before the blow-pipe it quickly 

 loses colour and becomes white, swells, and is changed with 

 but little difficulty into a white enamel. Pieces, which seem to 

 have been exposed to the air for some time, have their surface 

 coated of a dark colour, and present the appearance of holes 

 corroded into them, and lined with a ferruginous dust, no doubt 

 from the decomposition of the Iron contained in this mineral. 



In general appearance Killinite seems nearly allied to Serpentiae 

 and has many points of resemblance to Nephrite ; from both of 

 these species, however, its fusibility before the blow-pipe, and the 

 chemical analysis, prove it to differ abundantly, as both these con- 

 tain at least 10 per cent, of lime, an earth of which scarcely an 

 appreciable quantity can be discovered in our mineral. From Ser- 

 pentine it may be more particularly distinguished by its containing 

 only a trace of Magnesia, which forms 37 parts in the hundred of 

 that mineral. Nephrite, and the varieties of Jade, contain at least 

 5 parts in the hundred of Soda, a substance not to be found in 

 Killinite. But the species with which there is the greatest rea- 

 son to apprehend a confusion, is Spodumene, which occurs in 

 the very same vein in which our mineral is found. But Spo- 

 dumene, besides presenting some differences in the chemical 

 analysis, as the greater proportion of Silex and of Lime, and 

 the absence of any trace of Manganese or Magnesia, may be 

 distinguished, 1st. by the greater specific gravity, which of the 

 specimen from Killiney is 3.06 ; 2dly, by the structure which pre- 

 sents natural joints in three directions, while these are observable 





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