Fire assay is a traditional method used to determine the concentration of precious metals, such as gold and silver, in ores and other materials. The process involves heating a sample in a furnace with a mixture of fluxes, which helps to separate the metals from impurities. The resulting molten material is then cooled and analyzed. After cooling, the solidified mass is crushed, and the precious metals are extracted for measurement. This technique is known for its accuracy and reliability, making it a standard practice in the mining and metallurgy industries for assessing the value of mineral deposits.