88 THE IRON ORE DISTRICT OF EAST TE&AS. 



2. NODULAR CONCRETIONARY ORES. 



Twenty-four analyses of these ores have been made, and with a few excep- 

 tions they appear to be sufficiently rich in metallic iron for furnace purposes. 



As a general thing such ores run low in silica, the highest being 17.20 per 

 cent. In this ore, although the silica may be somewhat high, it contains 3.17 

 per cent of alumina, only 0.19 of sulphur, and has only a trace of phosphorus, 

 while the total percentage of metallic iron (49.58 per cent) places it in the 

 rank of workable ores. 



No. 735 has a total percentage of metallic iron of 51.77. Its alumina 

 amounts to 4.63 per cent, sulphur only eleven-hundredths of one per cent, 

 and of phosphorus only a trace has been found. The other ores of this group 

 are generally low in silica, most of them ranging from less than two to about 

 ten per cent. 



In sulphur and phosphorus the nodular ores are also low. In sulphur the 

 highest shows 0.92 per cent of sulphuric acid, or about three-tenths of one 

 per cent of sulphur. The quantity of sulphur in these ores is so small that by 

 any of the ordinary modes of roasting and washing practiced in the working 

 of this class of ores this impurity can be easily and quickly eliminated. In 

 phosphorus the highest amount shown is fourteen-hundredths of one per cent. 

 Six of the ores analyzed give each this amount. Some of the most extensively 

 developed ores of this class in the county, however, only show traces of phos- 

 phorus. 



The analyses given have all been made from fair average samples, and the 

 percentages of metallic iron shown could easily be enhanced by picking speci- 

 mens and by roasting, so as to drive off the contained water and sulphur be- 

 fore analyses. 



3. CONGLOMERATE ORES. 



Eight analyses of this class of ores have been made, and the results do not 

 justify the use of these ores for the manufacture of metallic iron. 



Of the ores found in Cass County, the geode or nodular concretionary 

 class, from an analytic point of view, are decidedly the best. They are also 

 the best and most extensively developed ore within the limits of the county, 

 and, from a practical point of view, appear to be the only ores capable of be- 

 ing profitably and economically worked. The laminated ores are but poorly 

 developed and are of a generally low grade, while the conglomerate ores, 

 though well developed in many portions of the county, especially in the neigh- 

 borhood of Queen City, are altogether too high in silica to be profitably or 

 economically utilized by any of the present methods of manufacturing iron. 

 These ores are, however, subject to magnetization by roasting at a red heat. 

 It may be possible to concentrate them by crushing, washing, and separating 



