Three Rectangle Shaped Fossil Coral Cabs

Here are three rectangle shaped polished fossil coral cabs of varying size. This 20 million year old agatized coral from Indonesia has a beautiful sunburst pattern.

These corals are approximately 20 million years old and are the remains of ancient reefs thrust up into the mountains by the collisions of tectonic plates. As these corals fossilized the original organic material was replaced by silica, iron, manganese and other minerals