Oyster shells have been used throughout history to help aid in construction. Quicklime is obtained from oyster shells when the CaCO3 in the shell is heated at an excess of 2000°F or about 1100°C and converted to calcium oxide (CaO), otherwise known as lime. This lime is then used in mortar mixtures and is called tabby. Tabby used in construction has been found commonly in Muslim territories such as Cordoba and Seville in the 15th century for military structures. Perhaps the most common tabby constructed buildings are 11th century British