Indium (In)

Indium metal ingot - one troy ounce - .99995 bullion     Indium was discovered in 1863 by German scientists Ferdinand Reich and Hieronymous Richter while testing for thallium in ores from the mining town of Frieberg. Instead of finding the characteristic green emission line they sought, they found an unknown blue emission line in their spectroscopic samples. They determined it must be a new element and named it indium due to its indigo spectral signature. Indium is a rare metal. Given absence of significant deposits it is currently only produced as a byproduct of base metal mining, mostly from zinc tailings.  Indium's mined production is currently about 40 times less than silver and estimated worldwide reserves of indium that can be recovered by economically viable means is 6000 tonnes. Approximately 18000 tonnes of silver and 2500 tonnes of gold are mined each year compared with about 670 tonnes of indium.  It has been estimated that at current mining rates, worldwide resources of in