Florida · Sedimentary
Coquina, Florida's native stone
A limestone made of shell fragments. It built the Castillo de San Marcos and absorbed cannon fire.
Coquina is a sedimentary rock made of broken seashells cemented together, found along parts of Florida's Atlantic coast. It is soft when quarried and hardens as it dries.
The Castillo de San Marcos in Saint Augustine, completed in 1695, is built of coquina. The stone's porous, slightly springy structure meant that cannonballs tended to lodge in the walls instead of shattering them, one reason the fort held.
It is a good reminder that stone choice is about behaviour, not only looks, and that Florida has its own stone story.
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