Jump to navigation Jump to search
Indium metal bar


A soft, malleable, silvery-white metallic element. Indium occur naturally in Zinc blende ores, such as Sphalerite, and in Tungsten, Tin, and Iron ores. It was discovered in 1863 by Reich and Richter. Indium has an abundance of 0.00001 % in the earth's crust. Indium is stable in air and is diamagnetic. It used as a plating over silver mirrors, in dental alloys, in semiconductors, and in nuclear reactor control rods.

Synonyms and Related Terms

In; indio (It., Esp.); Índio (Port.)


  • Flammable solid.
  • Hygroscopic.
  • Contact may cause irritation.
  • Fisher Scientific: MSDS

Physical and Chemical Properties

  • Flame color is deep blue.
  • Softer than lead and leaves a mark on paper.
Composition In (atomic no. 49)
CAS 7440-74-6
Mohs Hardness 1.2
Melting Point 156.4 C
Density 7.3 g/ml
Molecular Weight atomic wt = 114.76

Resources and Citations

  • The Merck Index, Martha Windholz (ed.), Merck Research Labs, Rahway NJ, 10th edition, 1983 Comment: entry 4980
  • The American Heritage Dictionary or Encarta, via Microsoft Bookshelf 98, Microsoft Corp., 1998