mining in the united states employment 1 annual production value continued coal 77 088 lead 3 437 000 metal 29 502 magnesium n a nonmetal 21 346 molybdenum 2 w sand and gravel 37 508 nickel ore stone 70 130 palladium 237 uranium 423 platinum 61 900 total 235 997 rare earth concentrates 27 600 silver 245 zinc 774 others 445 number of mines 8 640 512 other sectors 12 413 industrial minerals excluding fuels 13 925 asbestos barite 11 boron b 0 506 top five producting bromine 159 order totals 2001 tonnage cement wyoming 368 749 masonry 477 west virginia 162 416 portland 6 350 kentucky 133 834 clays includes ball bentonite 4 pennsylvania 74 146 common fire fuller s 5 texas 45 042 kaolin 467 170 diatomite 174 ten mineral producing feldspar 44 100
