296 ANNUAL REPORT SMITHSONIAN INSTITUTION, 1921. 



ated rocks from the Sudbury district, Ontario, and also one of the 

 cobalt nickel ores from Cobalt, Canada. 



The principal ores of manganese are the oxides, of which there are 

 numerous forms difficult to distinguish by the naked eye. The 

 principal ones are psilomelane, which sometimes occurs in interesting 

 botryoidal forms, and pyrolusite; more rarely manganosite, haus- 

 manite, braunite, polianite, and manganite. With these oxides are 

 included the silicate, rhodonite, and the carbonate, rhodochrosite, 

 which are sometimes utilized industrially. 



Recent advances in the methods of the manufacture of steel 

 have brought into use a number of minerals which until within a 

 few years were of scientific interest only. A special effort was 

 made, particularly during the Great War, to bring together the full 

 series of these ores here displayed. With the cooperation of Mr. 

 Frank L. Hess, of the United States Geological Survey, this was 

 eminently successful. The series includes the ores of tungsten — 

 wolframite, ferberite, tungstite and scheelite; ores of vanadium — 

 hewettite, patronite, and vanadinite; ores of titanium — mcnaccanite 

 (ilmenite), brookite, and rutile; ores of uranium — uraninite and 

 pitch-blende and molybdenite, an ore of molybdenum. Particularly 

 striking is the large mass of scheelite, weighing 2,500 pounds, from 

 the Atolia mines of California, and the ferberite from Boulder 

 County, Colo., weighing 1.500 pounds. Among the vanadium ores 

 those of Peru are perhaps of the greatest interest and warrant the 

 following transcript from the label. They were secured for the 

 Museum through the cooperation of Mr. D. F. Hewett, likewise of 

 the U. S. Geological Survey. 



Vanadium, a rare element allied to phosphorus, is found in 

 unusual concentration in the Department of .Tunin in 

 central Peru, a region occupied by faulted Juratrias and 

 Cretaceous sediments and injected by a great variety of dikes. 



The deposit is a lens-shaped mass occupying a fault, and is 

 composed mainly of (1) quisqueite, (2) patronite, and (3) a 

 cokelike hydrocarbon. In the weathered zone a number of 

 brighter colored, oxidized and hydrated compounds are found, 

 such as hewettite and pascoite. The material was probably 

 forced into the sediments while in plastic and homogeneous 

 condition, and the segregation took place later. 



The ores are roasted to drive off the volatile matter and the 

 vanadium is extracted from the residue. The chief value of the 

 element lies in its power to greatly increase the hardness and 

 toughness of steel, when added in quantities up to 1 per cent; 

 but various compounds of vanadium find extensive utilization 

 in the chemical and metallurgical industries. 



The titanium ores (rutile) of Virginia, it ma}^ be added, are unique 

 and the only ones of their kind worked to-day in America. The ma- 

 terial is shown both in the gangue and as concentrates, which are 



