a rare metallic element, soft, white, malleable, and easily fusible, found combined in various ore minerals, especially sphalerite: so called from the two indigo-blue lines in its spectrum. Symbol: In; atomic weight: 114.82; atomic number: 49; specific gravity: 7.3 at 20°C.
Origin of indium
1860–65; < New Latin, equivalent to ind(icum) indigo + -ium-ium
A soft, malleable, silvery-white metallic element that occurs mainly in ores of zinc and lead. It is used in the manufacture of semiconductors, in bearings for aircraft engines, and as a plating over silver in mirrors. Atomic number 49; atomic weight 114.82; melting point 156.61°C; boiling point 2,080°C; specific gravity 7.31; valence 1, 2, 3. See Periodic Table.