Placer gold was discovered in Washington in the 1850′s. However, placer mining did not become particularly active until discoveries were made in the 1860′s on Peshastin Creek in Chelan County and on Swauk Creek in Kittitas County.  During those early years and into the 1900′s, prospecting was general and it is possible that many streams were overlooked in the search for more worthwhile placer locations.   It is impossible at this time to determine the total amount of placer gold produced in the state of Washington.  The records for the period prior to 1900 are fragmentary at best and were not broken down to a county basis.  The many localities reporting locations of placer gold may indicate the parts of the state where prospecting may be advantageous today.  In June, 1975 the 44th Legislature of the State of Washington designated petrified wood as the state gem because of its beauty and abundance.  Petrified wood is found throughout the state and is symbolic of early forests.  It also represents a period of geological time when extensive volcanism buried great forests with volcanic ash and basaltic lava. According to the U.S. Bureau of Mines, Washington State is within the top ten producers of gemstones in the nation.  Petrified wood, agates, crystals and fossils are eagerly sought be many rockhounds.  Rockhounding — often defined as the collecting of rocks, minerals and fossils – along with jewelry making are important economic activities of the state.  In recent years, professional collectors have recovered crystals from Washington locales which are now housed in many museums including the Smithsonian.  The most notable and some of the finest gems in the world are bright red realgar crystals from Green River. Spectacular crystals of amethyst scepter (Denny Mountain), autunite (Mt. Spokane), grossular garnet (Vesper Peak) and pyrite (Spruce Peak) are by far considered the best in the nation.

The discovery of precious fire opal in a well seven miles northeast of Pullman in 1890 led to the first significant recovery of gem materials in Washington. Mine buildings were erected, and operations began in July of 1891 in what became known as Gem City. According to the U.S. Bureau of Mines, Washington State is within the top 10 producers of gemstones in the nation. Petrified wood, agates, crystals, and fossils are eagerly sought by many rockhounds of the state.