266 FINLAY 



The augite is light green. It differs from the usual varieties 

 of this mineral in never showing borders indicative of an in- 

 crease in the soda molecule. It is never tinged with violet. 

 Rarely it may be seen as if grown out from the ends of the 

 amphibole. 



Brown biotite in thin lath-shaped plates .5 mm, in length is 

 present as an accessory. It is notable for its inclusions, acicular 

 transparent prisms of an undetermined mineral resembling rutile. 

 They are usually inclined to the base at a sharp angle. Mag- 

 netite is rare, apatite and titanite common. 



The specimen of the nephelite syenite (Baril type) analyzed 

 by Dr. H. S. Washington, represents the average grain and 

 mineralogy of the rock along the north end of the Baril range. 

 Nephelite makes up about 18 per cent, of the whole. Augite, 

 hornblende and biotite are ail present. Apatite is conspicuous, 

 and titanite may be easily seen in the hand specimen. 



The results of analysis are given below, column I. Numbers 

 II, III and IV are placed beside it for reference. 





I. 



II. 



III. 



IV. 



SiO^ 



58.40 



59.01 



60.39 



51.90 



A1203 



20.25 



18.18 



22.51 



22.54 



FeP3 



1.78 



1-63 



.42 



4-03 



FeO 



2.41 



3.65 



2.26 



3-15 



MgO 



•49 



1.05 



•13 



1.97 



CaO 



311 



2.40 



•32 



3-II 



Na^O 



7.01 



7-03 



8.44 



8.18 



K2O 



5-39 



5-34 



4.77 



4.72 



HjQiio 



.27 



.15 







Hpig-^ 



.57 



•50 



.57 



,22 



CO2 



none 





trace 





TiO., 



•25 



.81 







Zr02 



none 



trace 







P2O5 



.20 



trace 







SO3 



.06 









CI2 



.02 



.12 







S 



none 









MnO 



trace 



•03 



.08 





BaO 



trace 



.08 







CaO 













100.21 



99.98 



99.89 



99.82 





Less for Clj 



•03 

 99-95 







