404 



UNITED STATES MINERAL RESOURCES 



,.,„„ MAJOR DETERMINANTS, U£. 



PRODUCTION, IN FLASKS OF 76 POUNDS PRODUCTION (EXCEPT PRICE) 



50,000 100,000 150,000 200,000 250,000 300,000 



New Almadon— first U.S. production 



New Idria discovered 



New Almaden closed— litigation 



Avg. mining cost per ton of ore, $170 

 Avg. grade of ore, 279 lb per ton 



New Almaden deep ore discovered 

 Scott furnace invented 



Avg. grade of ore, 47 lb per ton 



New Almaden "almost exhausted" 

 Avg. mining cost per ton of ore, $9 



Texas— first production 

 N«wada— first production 



United States becomes 

 a net importer of mercury 

 Herreshoff furnace adopted 

 Oregon— first sustained production 

 Rotary furnace successful 

 New Idria closed-litigation 



Avg. grade of ore, 10 lb per ton 

 Arkansas— first production 



The only years when production 

 was reported from all 10 states 

 Avg. mining cost per ton of ore, $13 



Secondary production reported 

 Index of metal-mining expenses, 74 



Secondary production increased 



Index of metal-mining expenses, 100 

 (Government assistance, exploration 



Avg. grade of ore, 7.6 lb per ton 



Index of metal-mining expenses, 114 

 Avg. grade of ore, 4.8 lb per ton 



'" 100 200 300 400 500 600 



AVERAGE ANNUAL U.S. PRICE PER FLASK, IN CURRENT DOLLARS 



Figure 46.— Mercury production and prices, 1850-1971. From U.S. Bureau of Mines Minerals Yearbooks. 



