192 ART. 2. — B. KOTÔ: 



1.648 KO 1.572 KA 12.063 SiO, ll,0 : RO 



Masanite 1.05 RO RA 7.67 SiO^ a 3.69 1.48 : 1 ß 26.3 



Tjpa Granite 1 1 7.7 3.91 1.7 : 1 



In comparison with average granite the masanite is shghtly lower 

 in acidity coefficient and alkahes. This is due to the ohgoclase 

 phenocryst which characterizes onr rock^\ 



From Os Ann's formula we have the following : — 



n 5.7 



n 5.7 ß 



Our rock closely resembles the granite of Woodstock '\ from 

 which, however, it slightly differs in the value of n, i.e. Nag : 

 ICO. The value of n in masanite is high in Na.O, the number 

 being 5.7 (=ß), that of Woodstock 4.9 {-r). This is due to the 

 presence of plagioclase. 



7. Grano- masanite. — This is essentially the same as the 

 preceding in its mode of (laccolithic) occurrence and composition. 

 Large masses of Korean neogranite belong to this category, and 

 occur extensively also in Chii-goku in Japan, in association with 

 crystal-porphyry. It is a huff- colour eel, coarse aplitic granite 

 easily crumbling into debris and sand. It is poor in coloured 

 minerals and accessories, being mainly composed of equiform and 

 oquant quartz and orthoclase. The components of this monoto- 

 nous leucocrate have the appearance of simultaneous crystalliza- 

 tions rudely intergrowing one another pegmatitically, though lack- 

 ing the regularity of the texture of graphic granite. The rock 



1) The specimen analysed w.as brought from the Kti-ryong coiiper mine, north of 

 Masan-pho. See ante, page 22. 



2) Osunn : " Versuch einer chemischen Classification tier Emptivgesteine, I. Die Tiefen- 

 gesteine." Tschermuks, M. P. .1/. Bd. XIX. Heft 5/6, S. 464. 



