Lime as the first cement: Since long, Lime has been used to make things like plaster and mortar. Lime is usually made by burning of limestone.Chemically; lime itself is calcium oxide (CaO) and is made by roasting calcite (CaCO3) to remove carbon dioxide (CO 2).ime has to be mixed with sand and other ingredients to take form of slaked lime cement, that can be used as mortar between stones or bricks in a wall or spread over the surface of a wall There, over the next several weeks or longer, it reacts with CO 2 in the air to form calcite again(artificial limestone).