eminent mineralogists, by some obvious marks of distinction iu 

 its external characters, and by the results of a chemical analysis. 



Having- observed on the south-western side of the hill of Killiney, 

 near Dublin, persons engaged in the clearing of land by the ope- 

 ration of blasting large blocks of Granite, I was led through curio- 

 sity to examine the broken pieces, in the hopes of meeting with 

 some unusual mineral substance. These expectations were strength- 

 ened by the consideration, that these blocks lay in the direction 

 of the remarkable junction of Granite and Mica-slate, which runs 

 from Killiney, through the Scalp, into the county of Wicklow. 

 Here I had the good fortune to meet with the mineral under 

 description, also in considerable abundance some fine specimens of 

 Spodumene, a species so rare, that, if we except the very small pieces 

 of it detected by Sir Charles Giesecke in Greenland, it has hitherto 

 been found only in one quarry in Sweden. They both occur at 

 KilUney in veins in granite. These veins consist of fine-grained 

 granite, of an inch or two in thickness, having their central parts 

 filled with Spodumene, with the present species, which, from its 

 locality, may be termed Killinite, large irregular pieces of Quartz, 

 imbedded crystals of felspar, and minute garnets. 



Killinite occurs imbedded in elongated prisms, the number of 

 whose sides, or the figme of whose terminations is not distinctly 

 observable : in one case, however, the prism indicated the octohe- 

 dral form. These prisms are frequently rifted across; they intersect 

 one another at various angles. The structure is lamellar ; the na- 

 tural joints cannot be perceived in more than one direction. The 

 lustre is shining, between pearly and silky. It is easily frangible. 

 The fracture is fine grained, uneven, with a dull lustre. Its colour 

 is usually of an olive green tinged with brown and yellow ; sometimes 

 of a light brown and of a pearly lustre. Its powder is of a greyish 



