Alloy are relatively similar in size, the atom exchange method usually happens, where some of the atoms composing the metallic crystals are substituted with atoms of the other constituent. This is called a "substitutional alloy". Examples of substitutional alloys include bronze and brass, in which some of the copper atoms are substituted with either tin or zinc atoms respectively. In the case of the interstitial mechanism, one atom is usually much smaller than the other and can not successfully substitute for the other type of atom in the crystals of the base metal. Instead, the smaller atoms become trapped in the
Sundown Tin and Copper Mine down 7 chains from the mine to the reverberatory furnace. The only building standing besides the furnace was the assay office. Firewood was swung across the creek to the furnace on wire ropes. The copper adit was driven , with winzes and drives off it, and a shaft connecting to the surface from the portal. The most recent smelting of 150 tons of ore produced 25 tons of matte containing 29% copper and 76oz silver and 6 dwt gold per ton matte. Mining recommenced in 1904, but was abandoned again in 1907, this time reputedly due to falling tin prices,