Brass than in brass produced by cementation. These may be "natural alloys" manufactured by smelting zinc rich copper ores in redox conditions. Many have similar tin contents to contemporary bronze artefacts and it is possible that some copper-zinc alloys were accidental and perhaps not even distinguished from copper. However the large number of copper-zinc alloys now known suggests that at least some were deliberately manufactured and many have zinc contents of more than 12% wt which would have resulted in a distinctive golden color. By the 8th–7th century BC Assyrian cuneiform tablets mention the exploitation of the "copper of the mountains"
American Brass Superfund site and extensive soil and groundwater contamination. After assessment by the EPA, it was added to the National Priorities List, in May 1999, for long-term remedial action. American Brass Superfund site The American Brass Superfund site is a former industrial site, located in Henry County, Alabama. American Brass Inc. (ABI) operated a brass smelter and foundry facility on the site between 1978-1992. Prior to its closure in December 1992, the company had been cited by the United States Environmental Protection Agency (EPA), and the Alabama Department of Environmental Management, (ADEM), on several occasions for Resource Conservation and Recovery Act (RCRA) violations,