Amphibole Amphibole is an important group of inosilicate minerals, forming prism or needlelike crystals, composed of double chain SiO 4 tetrahedra, linked at the vertices and generally containing ions of iron and/or magnesium in their structures. Wikipedia https://en.wikipedia.org/wiki/Amphibole 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.