190 ECONOMIC GEOLOGY 



ilmenite, FeO,TiO 2 . The last three are used in the manufacture 

 of chrome steel, tungsten steel and titanium steel. 



(4) Those used in the extraction of an included metal. For 

 gold and silver; pyrite, marcasite, and pyrrhotite. For nickel; 

 pyrrhotite. Practically all the nickel for domestic consumption 

 in the United States comes from the nickel-bearing pyrrhotite 

 deposits of Sudbury, Ontario, a few tons of nickel only being 

 produced at Mine La Motte, Missouri. 



The sulphides, arsenides, and phosphates of iron play no part 

 in the metallurgy of the metal in America because of the deleteri- 

 ous effect of each upon the resulting steel. The supply of the 

 metal comes therefore from the oxides, the hydrous oxides and 

 the carbonate. 



Origin of The Ores or Minerals. Native iron is quite widely 

 distributed as a primary mineral in the basic intrusives as dia- 

 base and dolerite. T. Andrews reports native iron in the basalts 

 of Ireland. F. Navarro found the metal in the basalts of Gerona, 

 Spain. F. F. Hornstein reports native iron in the basalts near 

 Cassel, Germany. C. H. Cook found native iron in the trap 

 rocks of New Jersey. According to G. W. Hawes, native iron 

 occurs in the dolerites of Dry River in the vicinity of Mount 

 Washington. The iron is enclosed in grains of magnetite which 

 may have been derived as a secondary mineral from the native 

 iron. According to E. Hussak, native iron exists in the Auriferous 

 gravels of Brazil. A. Daubree" and E. Meunier have reported 

 the metal from the gold washings in the Urals. These placers 

 contained traces of platinum but no nickel. 



The largest and the most important body of native iron ever 

 reported was discovered by A. E. Nordenskiold in 1870 at Ovifak, 

 Disco Island, on the western coast of Greenland. Large masses 

 or iron, sometimes weighing 20 tons, are encased in the basalt or 

 weathered out in boulder-like or lenticular forms. It was first 

 reported to be of meteoric origin. Lieutenant Peary brought 

 some of these boulder-like masses of iron to the United States, 

 and they have since been proven to be of terrestrial origin. 



According to F. W. Clarke, they closely resemble meteoric iron, 

 for they responded to Widmannstatten figures when etched, con- 

 tained the rare mineral lawrenceite, which is a hydrous ferrous 

 chloride, and was associated with magnetic pyrite and graphite. 

 Another proof of its terrestrial origin is the absence of schreiber- 

 site, the phosphide of iron, which is common in meteorites. 



