1899] Mineral Resources of the Ottawa District. 29 



stone. The crystals here were of a large size, sometimes as 

 much as three feet across, and many^ of them so clear that plates 

 two and three feet long by nearly a foot in breadth were 

 obtained. The mica here was dark coloured as might be ex- 

 pected from the dark colour of the containing rock, and a large 

 quantity of excellent mica was extracted before the deposit was 

 exhausted. 



A very pretty purple-tinted mica is also sometimes found in 

 cases where a dyke of light-tinted grar^ite cuts the limestone, 

 but as yet has not been obtained in quantities to be of economic 

 value. 



Iron Ores. 



The iron ores of this district are divisible into several classes 

 and occur at several horizons. The principal workable deposits 

 are magnetites, though several mines have been opened on 

 hematite ores, and sometimes both varieties are associated, as 

 in the case of the Haycock mine and at several points in Ren- 

 frew county. Of the magnetic variety there are also two kinds, 

 viz., the titaniferous and the true magnetites, and each of these 

 is found in its peculiar country rock. Thus in the case of the 

 titanium ores it may be said that they usually occur in anortho- 

 site rocks, which are a recent intrusion in the gneiss and lime- 

 stones, and the amount of titanic acid in these sometimes reaches 

 45 per cent , which renders the ore practically useless on account 

 of its great refractibility, and the consequent large amount of 

 fuel necessary to reduce it to a state of metallic iron. Attempts 

 have been made from time to time to utilize this ore, but always 

 with disastrous results to those interested. 



The true magnetites are found at many points and furnish 

 an ore often of great purity and value for smelting purposes. 

 They occur in the vicinity of Hull where they were mined ex- 

 tensively, and where they were also smelted for some years, 

 though operations in this locality have now been suspended for 

 nearly a quarter of a century. In Bristol also there are large 

 deposits of this ore which have also been extensively worked, 

 but its value is to some extent affected injuriously by a certain 





