174 A POPULAR EXPOSITION OF THE 
associated with small orange-red grains of rutile. The same substance 
(according to Sir W. Logan,) occurs also, mixed with magnetic iron 
ore. in a thick bed im serpentine, in Vaudreuil, Beauce County, C.K. 
Magnetic Iron Ore.—Iron-black, with sub-metallic lustre and black 
streak. Occurs in monometrie crystals (octahedrons and rhombic 
dodecahedrons, figs. 26 and 27), in amorphous masses of a granular or 
lamellar structure, and also in small grains. Strongly magnetic, often 
with polarity. H.5.5-6.5; sp. gr.4.9-5.2. Infusible, or nearly so. 
One hundred parts contain: Oxygen, 27.6; iron, 72.4; (or sesqui- 
oxide of iron, 69; protoxide of iron, 31.) This when pure, is the 
most valuable of all the iron ores. 
Its black streak, and strong mag- 
netism, (and, when crystallized, its 
form), easily distinguish it from spe- 
cular iron cre. in the Laurentian 
rocks of Canada, it occurs in vast 
beds, rendering this Province one of Fig. 27. 
the. richest iron-containing countries of the world. It occurs also 
abundantly amongst the metamorphosed Silurian strata of the Eastern 
Townships. Its principal ‘‘Laurentian’’ localities comprise: the 
Townships of Marmora, Belmont, and Madoc, with those of South 
Sherbrooke, Bedford, and Crosby, in Canada West ; and the Town- 
ships of Hull aud Litchfield, on the Ottawa, in Canada East. The 
supply at these localities is apparently inexhaustible. The Townships 
of Bolton and Brome, and the Chaudiére Valley, may be cited amongst 
the localities of this ore in the metamorphic district south of the 
St. Lawrence. In this district, however, as remarked by Sir William 
Logan, its value is much lessened by admixture with titanic iron, 
chlorite, &c. In the form of black magnetic sand (either alone or 
mixed with zserine, ), this ore is also of exceedingly common occur- 
rence on the shores of many of our lakes, islands, &c. The black 
iron-sand of the Toronto ‘“ Peninsula”’ is a well-known example. 
Fig 26. 
Iserine.—This is a black titaniferous iron ore, bearing the same re- 
lation to Magnetic Iron Ore that Ilmenite bears to Specular Iron. 
It occurs chiefly in the form of magnetic sand, or in small granular 
masses, mixed with magnetic iron ore. It occurs with “ iron sand”’ 
on our lake shores, &c., and probably with magnetic iron in the 
Eastern Townships. It can only be distinguished from the latter 
mineral by a blow-pipe (or other chemical) examination. Fused on. 
