49In Indium

Year Discovered


Discovered By

Ferdinand Reich and Hieronymous Richter of Germany

Biological Rating

Not necessary for life.


Named for the color indigo, which is a prominent color in indium’s spectra, indium is a very soft, very shiny silvery-white metal. It was once thought to be very rare, but now is believed to be fairly abundant. It is a stable metal, being unaffected by water and air, but does react with most acids. It makes mirrors as good as silver does, with the added bonus of not corroding like silver. It has a low melting point and is used in making low melting alloys for safety devices and solders. Indium, like gallium, remains a liquid over a large temperature range. Some indium compounds are used in transistors, photoconductors, photocells and thermistors (resistance thermometers).  It is used for electrial conduction in flat panel displays. Indium has the odd property of producing a high-pitched scream when bent.

image of refined indium


Biological Benefits

Indium has no known biological use. It does act to stimulate the metabolism.

Role in Life Processes

No known benefits for life processes.


Some indium is found in pure form, and it occurs in only a few minerals, such as indite. Most indium is obtained as a by-product zinc processing and is recovered from residues left from electrolytic refining of zinc. Indium is mined in South Korea and China (top producer).