16 ROYAL SOCIETY OF CANADA 



bluish colour gradually fading in passing outward to the white or pale 

 greyish nepheline. In thm sections under the microscope it is seen to 

 occur in in-egular strings or vein-like forms cutting across and among 

 the other constituents. In certain portions of the area it occurs in very 

 large masses, notably on lot 25, concession XIV of Dungannon. The 

 presence of the sodalite at this locality has been proved over a length of 

 some 250 feet with a Avidth of from forty to fifty feet, and it is stated to 

 be even more extensive than the present developments have shown. Suffi- 

 cient quarrying has, however, been done to prove this occurrence to be of 

 distinct economic importance, as it is quite possible to secure blocks of 

 sodalite weighing several tons. In 1906 a shipment was made of 130 

 tons of what was considered suitable material, to be used in the decora- 

 tion of the residence of Sir Ernest Cassell in Park Lane, Hyde Park, 

 London, England. This property has been known as the " Princess 

 Quarries, '' although a company has not yet been incorporated. It is 

 stated to be the intention of the ovmers to instal a complete plant not 

 only for quarrying the sodalite with channelling machines but sawing it 

 into slabs of suitable thickness. Other exposures showing large masses 

 of beautifully coloured sodalite also occur on lots 25 and 29, con. XTII 

 of Dungannon. At the first mentioned locality, preliminary development 

 work consisting of stripping and some blasting has shown the presence 

 of several large patches of the sodalite. At Craigmont in Eaglan town- 

 ship and on lot 34, concession V. of the township of Brudenell, patclu'.- 

 of deep blue sodalite occur in a nepheline syenite made up in addition 

 to this sodalite of a beautiful pale salmon nepheline and grey plagioclase, 

 the association producing a rock which has a very pleasing effect. The 

 colour in this mineral varies from a very dark cobalt blue to very pale 

 bluish, the colour fading rapidly when exposed to the action of the 

 weather. It is susceptible of a high polish and is eminently suitable for 

 inside decorative work. It is often associated with more or less magnetite 

 and biotite, and displays veinlets of reddish and whitish feldspar which 

 was shown on analysis by Dr. Harrington to be orthoclase. A sample 

 in the museum of the Geological Survey shows a crystal of hastingsite 

 several inches in length and perfectly terminated, completely enclosed in 

 the sodalite. Most of the material is compact with a multitude of ver}' 

 fine cracks which may be due to the shocks of blasting. The specimen 

 selected by Dr. Harrington for analysis showed distinct dodecahedral 

 cleavage and vitreous lustre. It was translucent and often sub-trans- 

 parent in ordinarily thin fragments, and its hardness was about 5.5. 

 Heated in a closed tube the sodalite became perfectly white, while be- 

 fore the blowpipe it fused easily with intumescence to a colourless glass. 



