Mercury

Mercury (element #80, symbol Hg) is a dense, heavy, silvery, metallic element which is liquid at room temperature.  Only three other elements (bromine, cesium and gallium) are liquid at or slightly above room temperature.  Mercury becomes solid at -40 ° F.  Mercury is often known as quicksilver, and the symbol for mercury, Hg, was derived from the Greek word for quicksilver, hydrargyrum.  Mercury vapor is highly toxic.  Pure mercury is found mainly in association with the ore mineral cinnabar.

Description

Mercury (element #80, symbol Hg) is a dense, heavy, silvery, metallic element which is liquid at room temperature.  Only three other elements (bromine, cesium and gallium) are liquid at or slightly above room temperature.  Mercury becomes solid at -40 ° F.  Mercury is often known as quicksilver, and the symbol for mercury, Hg, was derived from the Greek word for quicksilver, hydrargyrum.  Mercury vapor is highly toxic.  Pure mercury is found mainly in association with the ore mineral cinnabar.

Relation to Mining

Native mercury is found in association with its ore mineral, cinnabar. In the U.S., mercury was historically mined in California, Arkansas, Oregon, Nevada, Idaho and Texas. Major world producers of mercury are Algeria, Kyrgyzstan, Spain and China. The U.S. imports much of the mercury it needs each year.

One reason for the decline in mining is that mercury vapor has been found to be extremely toxic. Laws, in the U.S., require reduction in mercury emissions from smokestacks and carefully controlled disposal of waste mercury and mercury compounds.

The demand for mercury has been met by the recycling of mercury from obsolete or worn out machines, scientific apparatus and batteries. It is also recovered as a by-product from gold mining operations in California, Nevada, and Utah. Historically, mercury was used to obtain gold from placer gold deposits but this process is no longer used in the U.S. and many other countries.

Uses

Mercury is used to manufacture chlorine and caustic soda (35%). Because it is a metal, mercury conducts electricity making it useful in electronics and electrical applications (30%). Mercury, for example, is necessary in fluorescent light tubes. Mercury was an important ingredient in batteries, but newer types of batteries use other metals. The remaining 35% of mercury usage is in scientific measuring instruments such as thermometers and barometers.