The George Adderley House (built 1903) in Marathon, Florida Keys is one of the premier examples of “tabby construction” in the state.
Tabby is a type of concrete made by burning oyster shells to create lime, then mixing it with water, sand, ash and broken oyster shells. Tabby was used by early Spanish settlers in present-day North Carolina and Florida, then by English colonists primarily in coastal South Carolina and Georgia. Revivals in the use of tabby spread northward and continued into the early 19th century. Tabby was normally protected with a coating of plaster or stucco.