JOURNEYS THROUGH KOREA. 189 



coloured orthoclase — the reverse of tliat of the Finnish rapakiwi 

 — j and the quartz (1 cm) is round, sometimes bipyramidal. 

 These two components make up the greater bulk. It is a modi- 

 fication of masanite and may fitly be called " masanophyre ", 

 and it may be used for decorative purposes. This excellent rock 

 was kindly analysed by Mr. S. Shimidzu, of the Geological Survey, 

 with the following result : — 



Molecular ratio. Molecular ratio in percentage. 



1,2613 S2M% 



9.47 



23 



86 



12 



18 



3.31 



3.19 



100.00 

 100.93 



According to the system of Lcewinson-Lessing, we have 



1.169 ÜO 1.481 RA 12.013 SiO, 

 ÏÎO 1.266 R2O3 10.789 SiO, 

 Crystal-porphyry RO 1.3 RA 10.8 SiO, 



Type Quartzporphyry R.Os R^O. 9 SiO, 



As compared with typical qua i-tz- porphyry our rock is shght- 

 ly lower in SiO, , but much higher in alkahes. I liave tried to 

 apply Osann's formula to the analytical numbers, but without 

 satisfactory results, as the alumina is too high. 



4. Eu te ct of el si te (eutectophyre) is the name given by the 



