Hierarchy classification:

1. top of the aat hierarchies
2. Materials Facet
3. Materials (hierarchy name)
4. materials (substances)
5. [materials by form]
6. [materials by chemical form]
7. compounds (materials)
8. aluminum oxide

Anotations

Scope note:

A synthetically produced aluminum oxide, a white or nearly colorless crystalline substance that is used as a starting material for the smelting of aluminum metal, as the raw material for a broad range of advanced ceramic products, and as an active agent in chemical processing. Alumina is derived from bauxite, a naturally occurring ore containing variable amounts of hydrous aluminum oxides.