Tabby concrete

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 Florida, then by British colonists primarily in coastal South Carolina and Georgia. It is a man-made analogue of coquina, a naturally-occurring sedimentary rock derived from shells and also used for building.

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.