152 



CEMENTS, LIMES, AND PLASTERS. 



pletion of the new organization, but it is expected that the properties 

 will shortly be opened on an extensive scale." 



Recently several large deposits of magnesite have been discovered * 

 in the township of Grenville, Argenteuil County, in the province of 

 Quebec. Large boulders of the mineral were found, and finally the 

 magnesite was found in place. One of these deposits, which showed 

 an outcrop 90 feet long and 20 feet broad, is in the north half of the 

 eighteenth lot of the eleventh range of Grenville township. Another 

 outcrop, 100 feet wide and traceable for a quarter mile in length, is 

 on the north half of the sixteenth lot of the ninth range. 



The following analyses of magnesite from these deposits were made 

 by G. C. Hoffmann, and are quoted from the report cited below.* 



TABLE 60. 

 ANALYSES OF MAGNESITE FROM QUEBEC, CANADA. 



It will be seen that this Canadian magnesite differs from all the 

 other magnesites known to commerce, in that it contains a comparatively 

 large percentage of lime carbonate as its principal impurity. 



Production and imports of magnesite. In the following tables (61 

 and 62) statistics regarding the domestic production and the imports 

 of magnesia and magnesite are given. It will be seen that in 1903 the 

 value of the United States production amounted to less than 3 per cent 

 of the total value of magnesia and magnesite used in this country. 



Analyses of commercial magnesite. As magnesite is simply mag- 

 nesium carbonate, a theoretically pure magnesite would consist of 47.6 

 per cent magnesia (MgO) and 52.4 per cent carbon dioxide (C0 2 ). De- 

 posits of magnesite, however, rarely yield any considerable amount of 

 material of this degree of purity, and commercial magnesite may con- 

 tain as high as 10 per cent or thereabouts of lime carbonate, silica, 

 alumina, iron oxide, etc. 



* Ann. Rep. Canadian Geol. Survey, vol. 13, Report R, pp. 14-19. 1903. 



