What is "radiolarite"

n. 1 (lb en uncountable countable) radiolarian ooze, or the sedimentary rock formed from it. 2 (rfv-sense) (lb en countable uncommon) A fossil radiolarian shell.

Radiolarite is a siliceous, comparatively hard, fine-grained, chert-like, and homogeneous sedimentary rock that is composed predominantly of the microscopic remains of radiolarians. This term is also used for indurated radiolarian oozes and sometimes as a synonym of radiolarian earth. However, radiolarian earth is typically regarded by Earth scientists to be the unconsolidated equivalent of a radiolarite. A radiolarian chert is well-bedded, microcrystalline radiolarite that has a well-developed siliceous cement or groundmass.