|
| TABLE 7 | ||||
| MINING METHODS USED AT SURFACE OPERATIONS IN | ||||
| THE UNITED STATES IN 2006, BY COMMODITY� | ||||
| (Percentage of total material handled) | ||||
| Preceded by drilling | Not preceded by drilling | |||
| Commodity | and blasting | and blasting1 | ||
| Metal ore: | ||||
| Beryllium | 100 | -- | ||
| Copper | 100 | -- | ||
| Gold | 100 | -- | ||
| Gold-silver | 100 | -- | ||
| Lead | 100 | -- | ||
| Lead-zinc | 100 | -- | ||
| Iron | 95 | 5 | ||
| Magnesium metal | -- | 100 | ||
| Molybdenum | 100 | -- | ||
| Silver | 100 | -- | ||
| Titanium | -- | 100 | ||
| Uranium | -- | 100 | ||
| Zinc | 100 | -- | ||
| Industrial minerals: | ||||
| Abrasives | 100 | -- | ||
| Barite | -- | 100 | ||
| Boron minerals | 100 | -- | ||
| Bromine | 2 | 98 | ||
| Clays | -- | 100 | ||
| Diatomite | 16 | 84 | ||
| Feldspar2 | 46 | 54 | ||
| Garnet | 45 | 55 | ||
| Greensand marl | -- | 100 | ||
| Gypsum | 98 | 2 | ||
| Iodine | -- | 100 | ||
| Iron oxide pigments | -- | 100 | ||
| Kyanite | 100 | -- | ||
| Lithium minerals | -- | 100 | ||
| Magnesite | 100 | -- | ||
| Magnesium compounds | -- | 100 | ||
| Mica, scrap | -- | 100 | ||
| Olivine | 46 | 54 | ||
| Perlite | 24 | 76 | ||
| Phosphate rock | 5 | 95 | ||
| Potash | -- | 100 | ||
| Pumice3 | 35 | 65 | ||
| Salt | -- | 100 | ||
| Sand and gravel: | ||||
| Construction | -- | 100 | ||
| Industrial | -- | 100 | ||
| Stone: | ||||
| Crushed | 99 | 1 | ||
| Dimension | -- | 100 | ||
| Talc4 | 94 | 6 | ||
| Tripoli | 61 | 39 | ||
| Vermiculite | 9 | 91 | ||
| Wollastonite | 100 | -- | ||
| Zeolites | 100 | -- | ||
| -- Zero. | ||||
| 1Includes drilling and cutting without blasting, dredging, mechanical | ||||
| excavation and nonfloat washing, and other surface mining methods. | ||||
| 2Includes aplite. | ||||
| 3Excludes volcanic cinder and scoria; included with "Crushed stone." | ||||
| 4Excludes pyrophyllite.� | ||||
Source: United States Geological Survey Mineral Resources Program