1856.] HAUGHTON GRANITES OF IRELAND. 



Table III. — Analyses of Granites. 



1/7 





1. 



2. 



3. 



4. 



5. 



Silica 



70-38 

 12-64 

 316 

 2-84 

 0-53 

 5-90 

 3-13 

 M6 



7300 

 13-64 

 2-44 

 1-84 

 0-11 

 4-21 

 3-53 

 1-20 



70-28 



16-44 



2-60 



204 



'5-79 



2-82 



70-32 



16-12 



3-20 



1-34 



'4-65 

 3-39 

 0-96 



74-24 



13-64 



1-40 



1-48 



"'3-95 

 2-72 

 1-20 



Alumina 



Peroxide of iron... 

 Lime 



Magnesia 



Potash 



Soda 



Loss by ignition... 



Totals 



99-74 



99-97 



99-97 



99-98 



98-63 





1 





6. 



7. 



8. 



9. 



Average. 



Silica 



70-82 

 14-08 

 3-47 

 * 2-65 

 0-31 

 4-64 

 2-31 

 1-39 



73-24 



15-45 



1-60 



0-99 



4-5'9 

 3-08 

 1-20 



73-20 



15-48 



1-72 



0-96 



"4-80 

 318 



73-28 



12-64 



200 



1-72 



"4-70 

 2-97 

 1-04 



72-084 

 14-459 

 2-399 

 1-762 

 0-105 

 4-803 

 3014 

 0-906 



Alumina 



Peroxide of iron... 

 Lime 



Magnesia 



Potash 



Soda 



Loss by ignition... 



Totals 



99-67 



10015 



99-34 



98-35 



99-532 





I 



No. 1. Dalkey Quarries; specific gravity = 2-647; a fine-grained granite, con- 

 taining both black and grey mica. This granite has been used in the 

 construction of Kingstown Harbour. 



No. 2. Fox Rock, county Dublin ; specific gravity = 2*638 ; a coarse-grained 

 granite, striking fire when struck with a hammer, and showing abundant 

 grey quartz. 



No. 3. Three Rock Mountain, county Dublio, Woodside Quarry; specific gravity 

 = 2-652; a coarse-grained granite, containing rhomboidal and hexa- 

 gonal plates of grey mica, speckled with grains of black mica. 



No. 4. Three Rock Mountain, county Dubhn ; fine-grained granite, with occa- 

 sional large plates of speckled mica, which appears to be characteristic 

 of the granite of this mountain. 



No. 5. Enniskerry, county Wicklow ; specific gravity = 2-633 ; a rather coarse- 

 grained granite, containing veins of black schorl. 



No. 6. Ballyknocken, county Wicklow ; specific gravity = 2-636 ; a fine-grained 

 durable granite, considered to be the best building-stone near Dublin. 

 The quarries are situated beyond Blessington, county Wicklow. 



No. 7. Kilballyhugh, county Carlow ; specific gravity = 2-616 ; a fine-grained 

 granite and a good building- stone ; it contains no trace of black mica. 



No. 8. Blackstairs Mountain, county Wexford; specific gravity = 2-622; a 

 medium-grained granite from Kiltealy, on the Wexford slope of Black- 

 stairs Mountain. 



No. 9. Ballyleigh, county Wexford ; specific gravity = 2-627 ; a fine-grained 

 granite, fi-om near Poulmounty Bridge, at the extreme southern bound- 

 ary of the main granite chain. 



The mean specific gravity of the specimens examined is 2-634. 





