Assay Office is a historic building in Boise, Idaho

Boise, Idaho

Boise is the capital and most populous city of the U.S. state of Idaho, as well as the county seat of Ada County. Located on the Boise River, it anchors the Boise City-Nampa metropolitan area and is the largest city between Salt Lake City, Utah and Portland, Oregon.As of the 2010 Census Bureau,...

. It is significant for its role in the history of mining in Idaho. During the first half of the 1860s, Idaho’s gold production was the third highest in the nation. Due to the difficulty of transporting bulky, heavy ores the long distance to the nearest U.S. Mint in San Francisco, there was great demand for an assaying

Metallurgical assay

A metallurgical assay is a compositional analysis of an ore, metal, or alloy.Some assay methods are suitable for raw materials; others are more appropriate for finished goods. Raw precious metals are assayed by an assay office...

 office in Idaho. Gold and other precious metals are not mined in a pure form.