Indium is a malleable, silvery-white metal found primarily in ores of zinc and tin .
The soft, semiprecious metal has a boiling point of 2,000 degrees C, melting point of 156.61 degrees C and a specific gravity of 7.31. Its name is derived from the indigo-blue color of its spectrum. Indium was discovered in 1863 in sphalerite, a sulfide ore of zinc, by Reich and Richter in Germany, but was not used commercially until 71 years later. Recovered almost exclusively as a byproduct of zinc, indium is softer than lead and can be refined to purities of up to 99.9999 percent. Solders and alloys are also important applications.