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. sedimentary rock
9. [sedimentary rock by composition]
10. chert
11. flint (rock)

Anotations

Scope note:

A velvety-black variety of cryptocrystalline quartz, siliceous shale, or similar substance used by jewelers for testing the purity of precious metal, especially gold, by the streak left on the stone when rubbed with the metal.