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. rock (inorganic material)
8. metamorphic rock

Narrower term/s

• [slate by form or function][+]
  • blackboard slate
  • roofing slate [+]
    • wrestler slate
  • structural slate
• [slate by color or quality][+]
  • gray slate
  • black slate
  • blue slate
  • green slate [+]
    • Vermont green slate
  • red slate
  • purple slate
  • banded slate

Anotations

Scope note:

A very fine-grained, foliated, non-layered metamorphic rock, generally produced by metamorphism of shale under relatively low pressure and temperature. It occurs in many varieties, including clay, hornblende, mica, talc slate, and others, all of which have the common property of splitting readily into thin plates.