[HOWARD] SOME OUTLIERS OF THE MONTEREGIAN HILLS 81 



of glass with phenocrysts and rounded grains of melanite, pleonaste, 

 nepheline, sodalite, biotite, and possibly monticellite. 



Melanite forms a host of minute rounded grains which are light 

 green to light brown in colour. These rarely exceed 0.05 mm. in 

 diameter. 



Pleonaste is present in irregular grains, about 0.15 mm. in dia- 

 meter, and is very dark green in colour; in fact, it is practically opaque 

 excepting along very thin edges. 



Nepheline, phlogopite, and sodalite are quite fresh and usually 

 occur in rounded grains up to 0.25 mm. in size. The phlogopite is 

 occasionally hypidiomorphic and then forms larger grains 1.0 to 

 2.0 mm. in diameter. These mica plates frequently include rounded 

 grains of nepheline. The phlogopite is pale brown in colour and is 

 slightly pleochroic. 



One group of rounded grains was observed which resemble 

 monticellite very closely. They are biaxial and negative, and polarize 

 in first order greys and yellows, and have a moderately high index of 

 refraction. The presence of monticellite would be quite in order in 

 rocks so high in lime, and with such a low silica content as this one, 

 although it may be stated that it was only found in the one section 

 from this locality. 



Chemical Analysis of Camptonite, Husereau Occurrence, Near St. Benoit 



Analysis by W. V. Howard 



Norms 



99.57 

 Spec. grav. 3.10 



6— D 



