No. 4.] HARRINGTON — CANADIAN MINERALS. 251 



above, aud this was surrounded in turn by an aggregation of 

 hornblende prisms. These three portions may be called respect- 

 ively A., B. and C. A. resembled in appearance much of the 

 ordinary pyroxene of the region, from which also it probably 

 does not differ much in composition. The specific gravity was 

 found to be 3-181, and it gave on analysis the following results: 



A. 

 Silica 50-868 



Almniua 4-568 



Ferric oxide 0-970 



Ferrous oxide 1-963 



Manganous oxide 0-148 



' Lime 24-438 



Magnesia 15-372 



Potash 0-497 



Soda 0-218 



Loss on ignition 1-439 



100-481 



This is the composition of an aluminous diopside or malacolite, 

 and, except in the larger proportion of iron, resembles that of 

 pyroxene from Grenville and Bathurst.^ The following analysis 

 of B., the white portion of the crystal, shows that, chemically, no 

 great amount of change had taken place. The specific gravity 

 (3-205) was also about the same as that of A : — 



B. 

 Silica 50-898 



Alumina 4-825 



Ferric oxide 1-741 



Ferrous oxide 1-358 



Manganous oxide 0-152 



Lime 24-392 



Magnesia 15-268 



Potash 0-150 



Soda 0-076 



Loss on ignition 1-200 



100-060 



It will be observed that although the total amount of iron in 



A. and B. is almost identical, more of it exists as ferric oxide in 



B. than in A. The quantity of alkalies is also only about one- 

 third of the amount found in A. 



*See analysis. Report of Progress, 1874-75, p. 302, and Geology of 

 Canada, 1863, p. 467. 



