Indium

Indium is a silvery-white post-transition metal that is remarkably soft and easy to shape. It melts at about 157 °C and can leave a pencil-like mark on paper. In nature, small amounts occur within other minerals, especially sphalerite, a zinc sulfide ore. Producers recover indium as a by-product of processing zinc ores, then purify it using electricity. Its best-known role is in flat-panel displays: indium tin oxide forms thin coatings that conduct electricity while letting light through. Other indium compounds are used in LEDs and some thin-film solar cells. The metal also forms part of low-melting alloys used as solders to join metal components.