Cast Stone is defined as “a refined architectural concrete building unit manufactured to simulate natural cut stone, used in unit masonry applications.” It is created to simulate all types of natural cut stone and is referenced in the International Building Code under Chapter 14, Anchored Masonry Veneer.

The earliest known use of cast stone dates to about 1138 and can still be seen at Carcassonne, France, a city that contains some of the finest remains of early architecture in Europe. Cast stone was first used extensively in London around 1900, and has gained widespread acceptance in America since the 1920s.

According to Gary Fry, president of the board of directors of the Cast Stone Institute, “Many lessons have been learned throughout this history, and they can be used to improve the mason contractor's experience with cast stone at the current state-of-the-art.” The requirements for Cast Stone are referenced in the current ASTM International C1364 Standard for Architectural Cast Stone, which was originally approved in 1997 and updated in 2007. Various trade groups published specifications as early as 1927.

Cast stone is generally built into a load-bearing masonry wall system, and used as an architectural feature, trim, ornament, or veneer in traditional commercial and residential buildings and other structures. It is most often specified as a replacement for full bed-depth natural dressed dimensional limestone.