Fossils in thin section

Radiolarians in thin section

Opaline silica tests, usually under 2 mm, often hollow perforated spheres or vases. Low birefringence and fine fibrous structure, similar to chert or chalcedony; pores are usually filled during alteration.

Age: Radiolarites range from the Upper Cambrian onward (see Radiolarite).

No openly licensed photomicrograph was available in our sources.

All fossil groups Carbonate classification