I must admit that I had zero knowledge on Indium, in fact didn't even know it existed. So for those who like to be informed I copied this for general reading. Enjoy.Discovery
Indium was discovered in 1863 by the German chemist Ferdinand Reich at the Freiberg School of Mines in Germany. Reich was studying a sample of a zinc mineral blend that he thought might contain the recently discovered element thallium. After roasting the ore to remove most of the sulfur, he applied hydrochloric acid to the remaining materials. He then observed a yellowish solid appear. He suspected this could be the sulfide of a new element, but since he was color blind, he asked fellow German chemist Hieronymous T. Richter to examine the sample's spectrum. Richter noted a brilliant violet-colored line, which did not match the spectral line of any known element.
Working together, the two scientists isolated a sample of the new element and announced its discovery. They named the new element indium, after the Latin word indicum, meaning violet. Unfortunately, their relationship turned sour when Reich learned that Richter had claimed to be the discoverer, according to the Royal Society of Chemistry(RSC).
Uses
More than a century after indium's discovery, the element still lay in relative obscurity since no one knew what to do with it. Today, indium is vital to the world's economy in the form of indium tin oxide (ITO). This is because ITO remains the best material to fill the growing need for LCD's (liquid crystal displays) in touch screens, flat screen TVs and solar panels.
ITO has several properties that make it perfect for LCD's and other flat panel displays: It is transparent; conducts electricity; adheres strongly to glass; resists corrosion; and is chemically and mechanically stable.
ITO is also commonly used to make thin coatings for glass and mirrors. When coated over the windshields of aircraft or cars, for example, ITO allows the glass to de-ice or de-mist, and it can reduce air conditioning requirements.
The growing demand for LCDs has increased indium's prices considerably in recent years, according to the RSC. However, recycling and manufacturing efficiency have helped create a good balance between supply and demand.
Indium is commonly used to make alloys and is often referred to as the "metal vitamin," meaning that tiny levels of indium can make a drastic difference in an alloy, according to the RSC. For example, adding small amounts of indium to gold and platinum alloys makes them much harder. Indium alloys are used to coat the bearings of high-speed motors and other metal surfaces. Its low-melting alloys are also used in sprinkler heads, fire-door links, and fusible plugs.
Indium metal remains unusually soft and malleable at very low temperatures, making it perfect for use in tools needed in extremely cold conditions, such as cryogenic pumps and high vacuum systems. Another unique quality is its stickiness, making it very useful as a solder.
Indium is used in the making of various electrical devices such as rectifiers (devices that convert an alternating current into a direct one), thermistors (an electrical resistor dependent on temperature) and photoconductors (devices that increase their electrical conductivity when exposed to light).
Source & abundance
Indium is rarely found uncombined in nature and is typically found in zinc, iron, lead and copper ores. It is the 61st most common element in the Earth's crust and around three times more abundant than silver or mercury, according to the U.S. Geological Survey (USGS). It is estimated to make up around 0.1 parts per million (ppm) in the Earth's crust. By weight, indium is estimated to be 250 parts per billion (ppb), according to Chemicool. Natural indium is a mixture of the isotopes I-115 (95.72 percent) and I-113 (4.28 percent), according to Encyclopaedia Britannica.
Most commercial indium comes from Canada and is around 75 tons per year. Reserves of the metal are estimated to exceed 1,500 tons. Cultivated soils are sometimes found to be richer in indium than non-cultivated soils with some levels as high as 4 ppm, according to Lenntech.
