Hierarchy classification:

1. top of the aat hierarchies
2. Materials Facet
3. Materials (hierarchy name)
4. materials (substances)
5. [materials by composition]
6. organic material
7. bituminous material
8. natural bituminous material

Narrower term/s

• peat[+]
  • dredge peat
• coal[+]
  • anthracite
  • bituminous coal
  • cannel coal
  • lignite [+]
    • jet (coal)

Anotations

Scope note:

A natural, solid, hydrocarbon substance, distinguishable from bitumen by being infusible and insoluble. When heated, however, pyrobitumens generate or transform into bitumen-like liquid or gaseous petroleum compounds. This class of natural bituminous material includes peat, lignite, and coal.