Indium is a chemical element with chemical symbol In and atomic number 49. It is a very soft, malleable and easily fusible post-transition metal is chemically similar to aluminium or gallium. Zinc ores are the primary source of indium. It is named for the indigo blue line in its spectrum that was the first indication of its existence in ores, as a new and unknown element.

Indium's current primary application is to form transparent electrodes from indium tin oxide in liquid crystal displays and touchscreens, and this use largely determines its mining production. It is widely used in thin-films to form lubricated layers. It is also used for making particularly low melting point alloys, and is a component in some lead-free solders.

Radioactive indium-111 is used in indium leukocyte imaging, a nuclear medicine test which uses the isotope as an imaging agent to follow the movement of leukocytes in the body.


Indium has a standard electrode potential of +0.34V, the same as thallium. Unlike its period 5 neighbour cadmium, indium is not a cumulative poison.Indium in nature consists of two primordial nuclides.

One unusual property of indium (shared only with rhenium) is that although it possesses a stable isotope, its most common (abundant) isotope (95.7%) is slightly and measurably radioactive. This isotope, indium-115 very slowly decays by beta emission to tin. This decay has a half-life of 4.41 × 1014 years, four orders of magnitude larger than the age of the universe and nearly 50,000 times longer than that of natural Thorium.


The base value of each unit of ranges between 10 and 40Ð per unit, with up to 2 units being found at any one time.

Presence on Mars: Very Rare

Martian Minerals
Group 1 | Group 2 | Group 3 | Group 4 | Group 5 | Group 6
Group 3 |Antimony | Astatine | Barium | Bismuth | Cesium | Francium | Hafnium | Indium | Iodine | Iridium | Lanthanum | Lead | Mercury | |Osmium | Platinum | Polonium | Radium | Radon | Rhenium | Tantalum | Tellurium | Thallium | Tin | Tungsten | Xenon|