Mercury (symbol Hg) was known to the ancient Hindus and Chinese, and was also found in Egyptian tombs dating back to 1500 BC. The ancient Greeks used mercury in ointments, and the Romans used it in cosmetics. Alchemists thought mercury turned into gold when it hardened.
Mercury, also called quicksilver, is a heavy, silvery, toxic, transitional metal. Mercury is the only common metal that is liquid at room temperatures. When subjected to a pressure of 7,640 atmospheres (7.7 million millibars), mercury becomes a solid. Mercury dissolves in nitric or concentrated sulfuric acid, but is resistant to alkalis. It is a poor conductor of heat. Mercury has superconductivity when cooled to sufficiently low temperatures. It has a freezing point of about -39 degrees Celsius and a boiling point of about 357 degrees Celsius.
Mercury is found in its pure form or combined in small amounts with silvers, but is found most often in the ore cinnabar, a mineral consisting of mercuric sulfide. By heating the cinnabar ore in air until the mercuric sulfide breaks down, pure mercury metal is produced. Mercury forms alloys called amalgams with all common metals except iron and platinum. Most mercury is used for the manufacture of industrial chemicals and for electrical and electronic applications. Other uses for mercury include its use in gold recovery from ores, barometers, diffusion pumps, laboratory instruments, mercury-vapor lamps, pesticides, batteries, and catalysts. A decline in mercury production and usage since the 1970s reflects a trend for using mercury substitutes due to its toxicity.
Prices - The average monthly price of mercury in 2007 fell by -12.8% yr/yr to $518.54 per flask (34.5 kilograms). That is down from the 2005 record high price of $774.04.
Supply - World mine production of mercury in 2006 rose by +3.5% yr/yr to 1,480 metric tons. The record low of 1,320 metric tons was posted in 1999 and the record high of 10,364 metric tons was posted in 1971. The world's largest miners of mercury are China with 74% of world production and Kyrgyzstan with 17%. China's production rose to 1,100 metric tons in 2006, which is more than five times the record low of 190 metric tons seen in 2001 and almost equal to its record of 1,200 metric tons posted in 1989. Spain is also a large producer but their data has not been available since 2003.
Demand - The breakdown of domestic consumption of mercury by particular categories is no longer available, but the data as of 1997 showed that chlorine and caustic soda accounted for 46% of U.S. mercury consumption, followed by wiring devices and switches (17%), dental equipment (12%), electrical lighting (8%), and measuring control instruments (7%). Substitutes for mercury include lithium and composite ceramic materials.
Trade - U.S. foreign trade in mercury is still relatively small but U.S. imports of mercury in 2006 fell by -55.7% yr/yr to 94 metric tons from last year's 10-year high of 212 metric tons. U.S. imports were mostly from Chile and Peru. U.S. exports of mercury in 2006 rose by 22.3% to a 13-year high of 390 metric tons.