The Florida Keys are the exposed portions of an ancient coral reef. The Keys were inhabited by the Caloosa Indians in the 1500s. Modern development began in the early 1900s. Quarries were developed to mine limestone, known as ‘keystone,’ to provide fill for railroad beds and embankments. The quarries were closed by the 1980s. In 1990, 2,800 square nautical miles (16 square kilometers) of coastal waters surrounding the Florida Keys were designated as a national marine sanctuary. Now, Keystone can only be harvested from dry land when landowners require it to be removed for construction projects.
The fossilized coral, taken from the ground in the Florida Keys from Key Largo to Matecumbe Key is at least 120,000 years old and was alive when the Keys were a living reef.
The coral is harvested form the ground by the last remaining company licensed to extract fossilized coral from the Keys. It can only be taken from the dry land and only when it’s a licensed construction project. A trencher cuts the coral into 6-8-foot wide boulders. The boulders are then sliced into two and three-inch thick slabs, using a 10-foot diamond saw.