<P> Mining is the extraction of valuable minerals or other geological materials from the earth usually from an orebody, lode, vein, seam, reef or placer deposits . These deposits form a mineralized package that is of economic interest to the miner . </P> <P> Ores recovered by mining include metals, coal, oil shale, gemstones, limestone, chalk, dimension stone, rock salt, potash, gravel, and clay . Mining is required to obtain any material that cannot be grown through agricultural processes, or created artificially in a laboratory or factory . Mining in a wider sense includes extraction of any non-renewable resource such as petroleum, natural gas, or even water . </P>

What is the method used to dig the metal ore from the ground called