 Mercury element Mercury is a chemical element with symbol HG and atomic number 80. It is commonly known as quick silver and was formerly named hydrogerum. The heavy, silvery deep-lock element, Mercury is the only metallic element that is liquid at standard conditions for temperature and pressure. The only other element that is liquid under these conditions is bromine, though metals such as cesium, gallium, and rubidium melt just above room temperature. Mercury occurs in deposits throughout the world mostly as cinnabar-mercuryxulfide. The red pigment vermilion is obtained by grinding natural cinnabar-synthetic mercuryxulfide. Mercury is used in thermometers, barometers, manometers, sphigmonometers, float valves, mercury switches, mercury relays, fluorescent lamps and other devices. Though concerns about the elements toxicity have led to mercury thermometers and sphigmonometers being largely phased out in clinical environments in favor of alternatives such as alcohol, or gallinstone-filled glass thermometers and thermistor, or infrared-based electronic instruments. Likewise, mechanical pressure gauges and electronic strain gauge sensors have replaced mercury sphigmonometers. Mercury remains in use in scientific research applications and in the Malcolm Fordental Restoration in some locales. It is also used in fluorescent lighting. Electricity passed through mercury vapor in a fluorescent lamp produces short-wave ultraviolet light, which then causes the phosphor in the tube to fluoresce, making visible light. Mercury poisoning can result from exposure to water-soluble forms of mercury such as mercuric chloride or methylmercury by inhalation of mercury vapor, or by ingesting any form of mercury.