


Chert FAQ - Golden Gate National Recreation Area (U.S ...
Feb 28, 2015· Chert is a sedimentary rock rich in silica. Franciscan chert is formed from the tiny silica shells ... 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. ... Bay Area chert possibly came ...
