How do geologists get the Radiolaria out of the chert?
The beautiful and intricate Radiolaria tests can be extracted from the chert by crushing it into small pieces and then putting it in a solution of hydrofluoric acid. This is the same acid used to etch glass. The acid dissolves away the less durable rock matrix, leaving the exquisite three-dimensional shells exposed. The tests are then photographed using a scanning electron microscope.
