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 quality]

Anotations

Scope note:

Metal or alloy that is not resistant to oxidation and corrosion in moist air; base metals are thus distinguished from "noble metal." Base metals are also usually of minimum monetary value, and are thus commonly distinguished from "precious metal" as well.