Chemical Element: indium

(Modern Latin: chemical element; from Latin, indicum, indigo [a blue Indian dye]; metal)

Chemical-Element Information

Symbol: In
Atomic number: 49
Year discovered: 1863

Discovered by: Ferdinand Reich (1799-1882), a German mineralogist, and Hieronymus Theodor Richter (1824-1898), a German mineralogist.


  • Reich suspected that a yellow precipitate he had obtained from a zinc ore might contain a new metal, but because he was color-blind, he had his assistant, Theodor Richter, examine it spectroscopically.
  • It was found and spectroscopically identified as a minor component in zincores.
  • Until 1924, a gram or so constituted the world’s supply of this element in isolated form.
  • In fact, it is probably about as abundant as silver.
  • Indium is a very soft, silvery-white metal with a brilliant luster.
  • The pure metal gives a high-pitched “scream” when bent.
  • It is useful for making low-melting alloys.
  • An alloy of 24% indium and 76% gallium is liquid at room temperature.
  • Canada produces the majority of the world’s supply of indium.
  • Indium would not normally be made in the laboratory as it is commercially available.
  • It is a by-product of the formation of lead and zinc.
  • Indium metal is isolated by the electrolysis of indium salts in water.
  • Further processes are required to make very pure indium for electronics purposes.
  • Among other uses, indium has the unique property of being able to “wet” glass and other surfaces, which makes it valuable for producing hermetic seals between glass, metals, quartz, ceramics, marble, etc.

Name in other languages:

French: indium

German: Indium

Italian: indio

Spanish: indio


Information about other elements may be seen at this Chemical Elements List.

A special unit about words that include chemo-, chem- may be seen here.