Mercury metal (from latin hydrargyrum = liquid silver) is shiny and silvery and the only metal that is liquid at room temperature. Mercury metal is known since ancient times, when it was believed to be something magical and also a cure for everything. More recently Mercury metal was and still is used in thermometers and barometers and in amalgams as filling for our teeth. Elemental mercury and many of its compounds are very toxic, so it should be avoided and not be used, if there are alternatives. Mercury metal can be sold only in small quantities and perfectly sealed for laboratory or display use.