CHAPTER II. 



THE IRON SERIES CONTINUED. HEMATITE, RED AND 

 SPECULAR. 



2.02.01. The sesquioxide of iron, F 2 O 3 , is always of a red 

 color when in powder. If it is of earthy texture, this color shows 

 in the mass, and the ore is called red hematite ; if the ore is 

 crystallized, the red color is not apparent, and the brilliant luster of 

 the mineral gives it the name specular hematite. The red hematites 

 are first treated. 



2.02.02. Example 6. Clinton Ore. Wherever the Clinton 

 stage of the Upper Silurian outcrops, it almost invariably contains 

 one or more beds of red hematite, interstratified with the shales 

 and limestones. These ores are of extraordinary persistence, as 

 they outcrop in Wisconsin, Ohio, and Kentucky in the interior, and 

 then beginning in New York, south of Lake Ontario, they run 

 easterly across the State. Again in Pennsylvania they follow the 

 waves of the , Appalachian folds, and extend south into West 

 Virginia and Virginia in great strength. They are found in east- 

 ern Tennessee and northwestern Georgia, and finally in Alabama are 

 of exceptional size and importance. The structure of the ore varies 

 somewhat. At times it is a replacement of fossils, such as crinoid 

 stems, molluscan remains, etc. (fossil ore) ; again as small oolitic 

 concretions, like flaxseed (flaxseed ore, oolitic Ore, lenticular ore) ; 

 while elsewhere it is known as dyestone ore. The ore in many 

 places is really a highly ferruginous limestone, and below the 

 water level in the unaltered portion it often passes into limestone, 

 while along the outcrop it is quite rich. 



2.02.03. In Dodge County, southeastern Wisconsin, the ore is 

 14 to 26 feet thick and consists of an aggregate of small len- 

 ticular grains. 1 In Ohio it outcrops in Clinton, Highland, and 



1 T. C. Chamberlain, Geol Survey Wis., Vol. L, p. 179. R. D. Irving, 

 " Mineral Resources of Wisconsin," M. E., VIII. 478; Geol. Survey Wis., 

 Vol. L, p. 625. 



