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. mineral

Anotations

Scope note:

Vitreous green iron silicate mineral, a member of the olivine group, named for the type locality, Fayal Island, Azores. The brittle stone was also produced synthetically as a component of slag separated in smelting at ancient iron working furnaces.