How is gold mined? Although gold is one of the world’s most precious commodities, the process of finding gold is hardly glamorous. Gold mining conjures up the image of a person wading in a shallow stream with an empty pan in his hand and hope in his eyes. Although searching for gold can still be done this way, there are much more effective ways to mine for gold. Gold mining became a big business back in ancient Rome. In fact, Romans developed a hydraulic mining system that used water to separate gold from rock. Rome's mining advances remained the industry standard for hundreds of years.

Hard Rock Mining
Hard rock mining occurs when instruments tunnel deep into the earth to extract rocks. Machines grind the rocks, and then miners begin the process of cyanide extraction, which involves mixing rock with sodium cyanide. The rocks used in this process are considered likely candidates for gold because of a history of finding gold in the general area. Zinc is added to the mixture, which then precipitates, or separates out, gold. Sulfuric acid is then added to remove the zinc. What remains is 99.9999% pure gold.

Metal Detecting
Gold can be mined with a special device known as a metal detector. Metal detectors are hand-held devices that people use to locate gold buried close to the surface of the ground. Many people use metal detectors on the beach, where they can walk around leisurely and search for buried treasures.

Sluicing
Sluicing is the process of extracting gold from a steady stream of water. It is used in small-scale mining. The main tool in sluicing is a container called a sluicing box. The sluicing box captures any gold in a special compartment and filters heavier materials, like rock.

Dredging
Dredging is closely related to sluicing. It uses a sluicing box that relies on a suction hose. Although this method is more sophisticated than sluicing, environmental agencies generally put limits on its operation because of its impact on fish.