Portland cement

Common type of powdery cementitious building material made from finely pulverized alumina, iron oxide, lime, magnesia, and silica burnt together in a kiln. When mixed with water and sand (or gravel) it turns into masonry mortar (or concrete) and, after a series of complex internal reactions, sets like a stone. Invented in 1824 by the UK bricklayer Joseph Aspdin (1779-1855), it gets its name from its resemblance (upon hardening) to the famous Portland limestone (obtained from quarries on the Isle Of Portland), the traditionally preferred choice for building churches, mansions, and palaces.