135 
Geological Relations of the East of Ireland \ 
loose blocks, the felspar having decayed, and left a singularly con- 
nected tissue of quartz, exhibiting amorphous masses, veins, and 
ramifications. 
More to the southward, around Knockatomcoyle, are great masses 
and rocks of very white quartz, which, although occupying a much 
greater space, perfectly correspond in appearance with those at Eagle 
hill, and hence they seem also to form inherent portions of the 
granite soil. 
§ 18. The minerals which I have incidentally observed disse- 
minated in the granite, or imbedded in the contemporaneous veins of 
granite and quartz, that traverse the rock, (which more particularly 
form their native seat,) are schorl, tourmaline, garnet, beryl, rock 
crystal, epidote, heavy spar, magnetic iron ore, galena, copper 
pyrites, and iron pyrites. But in addition to these, I am indebted 
to Dr. Taylor for the information, that he has discovered in the 
granite, malachite, arsenical pyrites, tinstone,* spodumene, and a 
new mineral, to which he has given the name of killinite.'f* Mr. 
Richard Griffith, jun. has found fluor spar on the Dalkey coast, 
forming druses of minute cubical crystals in small cavities in the 
granite; and rock crystal under the same circumstances is not of 
uncommon occurrence. And I have met with hexahedral prismatic 
crystals of felspar, 3 inches by 2, and even 4 inches by 3 in size. 
* It is an interesting fact that this metal should at length have been discovered in rock 
in this country, although’Tound only in a contemporaneous vein traversing a loose block of 
granite ; for its existence in the county of Wicklow, in the form of stream tinstone, had 
been ascertained several years ago by the operations of the directors of the works at 
Croghan Kinshela. 
+ Yid. The author’s paper in the Transactions of the Royal Irish Academy, vol. xiii. 
containing a description and analysis of this mineral. I have since had the satisfaction of 
finding also at the south-western foot of Rochetown hill, three small blocks of granite, 
traversed by contemporaneous veins of large grained granite, which contain likewise 
killinite and spodumene. 
