History

(from the brilliant indigo line in its spectrum) Discovered by Reich and Richter, who later isolated the metal. Until 1924, a gram or so constituted the world's supply of this element in isolated form. It is probably about as abundant as silver. About 4 million troy ounces of indium are now produced annually in the Free World. Canada is presently producing more than 1,000,000 troy ounces annually.

Sources

Indium is most frequently associated with zinc materials, and it is from these that most commercial indium is now obtained; however, it is also found in iron, lead, and copper ores.

Properties

Indium is available in ultra pure form. Indium is a very soft, silvery-white metal with a brilliant luster. The pure metal gives a high-pitched "cry" when bent. It wets glass, as does gallium. 
A Periodic Table of the Elements at Los Alamos National Laboratory