Mercury

Mercury is a dense, silvery liquid metal with unique properties that make it useful in thermometers, barometers, electrical switches, fluorescent lamps, and certain industrial chemical processes. It is also used in the amalgamation process for gold and silver recovery from low-grade ores. Mercury is recovered from cinnabar by simple roasting in air, which oxidises the sulphide and releases mercury vapour that is condensed and collected. Its extreme toxicity, however, demands scrupulous handling, as mercury vapour and organic mercury compounds are highly damaging to the nervous system.