38 PENTTI KSKOI-A. M.-N. Kl. 



By separation vvitli Clcrici's solution there was obtained: 



Pyroxene 57.7 ^Vo 



Garnet 34. 1 „ 

 Quartz » 



Mica / '-^ " 



Kutilc 0.3 „ 



100.0 ^/b 

 Sp.g. = 3-415 <t- 131 



A calculation from the specific volumes of the minerals in this rock 

 gave the specific gravity of the rock as 3.43, in close agreement with 

 direct of)sei-vation. 



The garnet was analyzed b}' the writer with the following result: 



^/0 Mol. numb. 



SiO.i 40-30 672 672 



liO., 



AI2O3 

 Fe.Oa 

 FeO 

 MnO 



MgO 

 CaO 



229 



6so 



100.59 



Sp.g. = 3.882 (t= 12°). 

 n^ = 1.7660. 

 1^0 : R.,03 : SiO., = 2.83 : i : 2.93. 

 Composition : (Fe^oMn.2Mg^.{Cai5).5( ALj^Fe,.). 



The following is the analysis of the pyroxene made bv the writer: 



' Less than o. i o 0/ü. 



