Heavy Metal Definition and List

Mercury droplets on surface
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A heavy metal is a dense metal that is (usually) toxic at low concentrations. Although the phrase "heavy metal" is common, there is no standard definition assigning metals as heavy metals. 

Characteristics of Heavy Metals

Some lighter metals and metalloids are toxic and, thus, are termed heavy metals though some heavy metals, such as gold, typically are not toxic. ​

Most heavy metals have a high atomic number, atomic weight and a specific gravity greater than 5.0 Heavy metals include some metalloids, transition metals, basic metals, lanthanides, and actinides. Although some metals meet certain criteria and not others, most would agree the elements mercury, bismuth, and lead are toxic metals with sufficiently high density.

Examples of heavy metals include lead, mercury, cadmium, sometimes chromium. Less commonly, metals including iron, copper, zinc, aluminum, beryllium, cobalt, manganese and arsenic may be considered heavy metals.

List of Heavy Metals

If you go by the definition of a heavy metal as a metallic element with a density greater than 5, then the list of heavy metals is:

  • Titanium
  • Vanadium
  • Chromium
  • Manganese
  • Iron
  • Cobalt
  • Nickel
  • Copper
  • Zinc
  • Gallium
  • Germanium
  • Arsenic
  • Zirconium
  • Niobium
  • Molybdenum
  • Technetium
  • Ruthenium
  • Rhodium
  • Palladium
  • Silver
  • Cadmium
  • Indium
  • Tin
  • Tellurium
  • Lutetium
  • Hafnium
  • Tantalum
  • Tungsten
  • Rhenium
  • Osmium
  • Iridium
  • Platinum
  • Gold
  • Mercury
  • Thallium
  • Lead
  • Bismuth
  • Polonium
  • Astatine
  • Lanthanum
  • Cerium
  • Praseodymium
  • Neodymium
  • Promethium
  • Samarium
  • Europium
  • Gadolinium
  • Terbium
  • Dysprosium
  • Holmium
  • Erbium
  • Thulium
  • Ytterbium
  • Actinium
  • Thorium
  • Protactinium
  • Uranium
  • Neptunium
  • Plutonium
  • Americium
  • Curium
  • Berkelium
  • Californium
  • Einsteinium
  • Fermium
  • Nobelium
  • Radium
  • Lawrencium
  • Rutherfordium
  • Dubnium
  • Seaborgium
  • Bohrium
  • Hassium
  • Meitnerium
  • Darmstadtium
  • Roentgenium
  • Copernicium
  • Elements 113-118

Keep in mind, this list includes both natural and synthetic elements, as well as elements that are heavy, but necessary for animal and plant nutrition.