  a gold rush is a period of feverish migration of workers to an area that has had a dramatic discovery of gold deposits. major gold rushes took place in the 19th century in australia, new zealand, brazil, canada, south africa, and the united states, while smaller gold rushes took place elsewhere. in the 19th and early 20th centuries, there were several major gold rushes. the permanent wealth that resulted was distributed widely because of reduced migration costs and low barriers to entry. while gold mining itself was unprofitable for most diggers and mine owners, some people made large fortunes, and the merchants and transportation facilities made large profits. the resulting increase in the world's gold supply stimulated global trade and investment. historians have written extensively about the migration, trade, colonization, and environmental history associated with gold rushes. gold rushes were typically marked by a general buoyant feeling of a "free for all" in income mobility, in which any single individual might become abundantly wealthy almost instantly, as expressed in the california dream. gold rushes helped spur a huge immigration that often led to permanent settlement of new regions and define a significant part of the culture of the australian and north american frontiers. as well, at a time when the world's money supply was based on gold, the newly mined gold provided economic stimulus far beyond the gold fields. gold rushes presumably extend back as far as gold mining, to the roman empire, whose gold mining was described by diodorus siculus and pliny the elder, and probably further back to ancient egypt. ==life cycle of a gold rush==   thumb|a man leans over a wooden sluice. rocks line the outside of the wood boards that create the sluice.  within each mining rush there is typically a transition through progressively higher capital expenditures, larger organizations, and more specialized knowledge. they may also progress from high-unit value to lower unit value minerals (from gold to silver to base metals). a rush typically begins with the discovery of placer gold made by an individual. at first the gold may be washed 
Gold_mining Gold_rushes History_of_mining