Hierarchy classification:

1. top of the aat hierarchies
2. Materials Facet
3. Materials (hierarchy name)
4. materials (substances)
5. [materials by composition]
6. inorganic material
7. metal
8. [metal by composition or origin]
9. nonferrous metal

Additional parents:

1. top of the aat hierarchies
2. Materials Facet
3. Materials
4. materials
5. materials by form
6. materials by chemical form
7. elements

Anotations

Scope note:

Zirconium is a metallic element having symbol Zr and atomic weight 91.22. It is obtained from zircon and other minerals and is commercially the most important ore. A hard metal resistant to heat and corrosion, it is much used in nuclear reactors, in alloys, refractories, and ceramics.