ODM2 Variable Name Controlled Vocabulary ODM2 Working Group A vocabulary for describing the name of Variables. Vermiculite Vermiculite is a hydrous phyllosilicate mineral. It undergoes significant expansion when heated. Exfoliation occurs when the mineral is heated sufficiently, and the effect is routinely produced in commercial furnaces. Wikipedia https://en.wikipedia.org/wiki/Vermiculite Added to support Critical Zone Observatory (CZO) data use cases.