Agatized Coral Fossil Geode Half Specimen

This remarkable agatized coral geode is a rare window into Florida’s prehistoric oceans — a coral colony that lived roughly 25 million years ago, then transformed over time into agate.

During the Oligocene to Miocene periods, thriving coral reefs covered much of what is now north-central Florida. A sudden, catastrophic, underwater mudslide or sediment collapse buried these reefs beneath layers of fine silica-rich sediment, sealing them off from decay. Over millions of years, silica-laden groundwater slowly replaced the coral’s interior structure with chalcedony and quartz.

Sliced open, this geode reveals a gorgeous botryoidal interior, where rounded, grape-like layers of translucent agate have formed within the fossilized coral cavities. Subtle luster and gentle curves create a mesmerizing organic texture — a natural sculpture shaped by ancient life and deep geologic time.

This specimen is just one half of the geode.

65x53x17mm

47g