Agatized (Fossil) Coral – Rare, Beautiful & Fascinating: 100 Years @FloridaMuseum https://www.floridamuseum.ufl.edu/100-years/object/agatized-fossil-coral/
Agatized Coral forms when silica replaces the original calcium carbonate skeleton of a coral colony. This replacement process creates beautiful specimens with cave-like appearances. Summary Agatized (Fossil) Coral (Siderastrea sp.) From Florida Lived ~34–28 million years ago (Early Oligocene)
Florida Museum photo by Kristen Grace Rare, Beautiful & Fascinating Online Exhibit
