Indium Indium is a chemical element with symbol In and atomic number 49. It is a post-transition metal that makes up 0.21 parts per million of the Earth's crust. Very soft and malleable, indium has a melting point higher than sodium and gallium, but lower than lithium and tin. Wikipedia https://en.wikipedia.org/wiki/Indium Added to support Critical Zone Observatory (CZO) data use cases. ODM2 Variable Name Controlled Vocabulary ODM2 Working Group A vocabulary for describing the name of Variables.