Background | Name | Sources | Uses | Substitutes and Alternative Sources
Background Indium is a soft, silver-white metallic element. Its atomic number is 49 and its chemical symbol is In. Indium was discovered in 1863 by the German chemists Ferdinand Reich and Heironymous Richter. They not only discovered this element, but also were the first to isolate pure indium. It was at first believed to be very rare. It is now known that it is relatively abundant in some but not all zinc sulphide (sphalerite or ZnS) ore deposits. Indium is very stable in both air and water; it does react with some acids. It forms only a very few rare minerals, such as indite, which is never abundant enough to be an ore of indium.
Indium has the unusual physical property that when it is bent (that is, when it is stressed) it creates a sound similar in pitch to a scream.
Indium is not necessary for any biological purpose. It has been shown that small amounts of indium cause an increase in metabolism.
