4.1" Agatized Fossil Coral Geode - Florida

This is a beautiful specimen of agatized coral from the Basin Deposits of Florida. This fossil coral is Miocene (25-32 million years) in age, and was formed when fine sediments covered shallow coral reefs. As silica rich groundwater seeped through the rock that was formed (and exposed as sea levels dropped), it replaced the calcium carbonate skeleton of the coral with chalcedony. There are a number of types of fossil coral present, but given the replacement destroys much of the original detail, more specific identification is difficult.

The chalcedony has crystallized in the botryoidal habit. What could be considered the back side of this specimen, still contains the fossil structure of the coral!