PEBBLE PROJECT RECORD OF DECISION ENVIRONMENTAL IMPACT STATEMENT USGS OPEN-FILE REPORT 02-303EPA, MINERAL COMMODITY PROFILES— GOLD (BUTTERMAN AND AMEY III, 2005) Mineral Commodity Profiles—Gold By W.C. Butterman and Earle B. Amey III Any use of trade, firm, or product names is for descriptive purposes only and does not imply endorsement by the U.S. Government Open-File Report 02-303 U.S. Department of the Interior U.S. Geological Survey U.S. Department of the Interior Gale A. Norton, Secretary U.S. Geological Survey P. Patrick Leahy, Acting Director U.S. Geological Survey, Reston, Virginia 2005 For product and ordering information: World Wide Web: http://www.usgs.gov/pubprod Telephone: 1-888-ASK-USGS For more information on the USGS—the Federal source for science about the Earth, its natural and living resources, natural hazards, and the environment: World Wide Web: http://www.usgs.gov Telephone: 1-888-ASK-USGS Although this report is in the public domain, permission must be secured from the individual copyright owners to reproduce any copyrighted material contained within this report. iii Contents Overview .............................................................................................................................................................................................1 Descriptive terms and units of measure........................................................................................................................................1 Historical background.......................................................................................................................................................................2 Gold in jewelry and ornamentation......................................................................................................................................2 Gold in other nonmonetary uses ..........................................................................................................................................3 Gold as a monetary metal......................................................................................................................................................3 Production and supply ...........................................................................................................................................................4 Mining in the United States...................................................................................................................................................8 Description........................................................................................................................................................................................10 Salient facts ...........................................................................................................................................................................10 Principal forms, alloys, compounds...................................................................................................................................10 Commercial grades, shapes, specifications ....................................................................................................................11 Sources .............................................................................................................................................................................................12 Primary....................................................................................................................................................................................12 Crustal abundance.....................................................................................................................................................12 Geochemistry..............................................................................................................................................................13 Mineralogy ..................................................................................................................................................................13 Gold deposits ..............................................................................................................................................................14 Reserves, reserve base, resources ........................................................................................................................16 Secondary ..............................................................................................................................................................................16 Other sources ........................................................................................................................................................................17 Production technologies ................................................................................................................................................................18 Exploration .............................................................................................................................................................................18 Mine development ................................................................................................................................................................18 Mining .....................................................................................................................................................................................19 Placer mining ..............................................................................................................................................................19 Lode mining .................................................................................................................................................................20 Ore processing ......................................................................................................................................................................21 Placer gold ..................................................................................................................................................................21 Lode gold .....................................................................................................................................................................22 Recycling...........................................................................................................................................................................................26 Uses ...................................................................................................................................................................................................27 Properties that determine use ............................................................................................................................................27 Use in industry and the arts ................................................................................................................................................27 Jewelry ........................................................................................................................................................................28 Electronic/electrical uses.........................................................................................................................................33 Dental and medical uses...........................................................................................................................................35 Other industrial uses..................................................................................................................................................37 Use as an investment good .................................................................................................................................................39 Competitive materials and processes ...............................................................................................................................39 Industry..............................................................................................................................................................................................39 Structure.................................................................................................................................................................................39 iv Mines ......................................................................................................................................................................................40 Refineries ...............................................................................................................................................................................42 Fabricators .............................................................................................................................................................................42 Jewelry ........................................................................................................................................................................42 Other manufacturers .................................................................................................................................................43 Traders....................................................................................................................................................................................43