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]

Narrower term/s

• radiolarite

Anotations

Scope note:

Non-clastic sedimentary rocks with a content of at least 50 percent silicon dioxide, either as quartz or as amorphous silica and cristobalite. Formation is the result of the accumulation of siliceous organic remains. Included are rocks that have formed as chemical precipitates, but not those of detrital or fragmental origin. The most common siliceous rock is chert.