ODM2 Variable Name Controlled Vocabulary ODM2 Working Group A vocabulary for describing the name of Variables. Tantalum Tantalum is a rare, hard, blue-gray, lustrous transition metal that is highly corrosion-resistant. It is part of the refractory metals group, which are widely used as minor components in alloys. Wikipedia https://en.wikipedia.org/wiki/Tantalum Added to support Critical Zone Observatory (CZO) data use cases.