While limestone is still the builders choice, it’s really hard to imagine a more practical solution than Cast Stone. With lower cost, durability, color availability, and all the other qualities, why would you use anything else?
As is very common in architecture, especially in Europe and North America, limestone is the builders’ choice for structural elements in and on buildings. In the Middle Ages, where it was available, limestone was a very popular building block. It is hard, durable, and commonly occurs in easily accessible surface exposures. Many medieval churches and castles in Europe are made of Limestone.
In the late 19th and early 20th centuries limestone gained popularity. Train stations, banks and other structures from that era are normally made of limestone. It is also used as a façade on some skyscrapers, but only in thin plates for covering, rather than solid blocks. It is long-lasting and stands up well to exposure. However, it is a very heavy material, making it impractical for tall buildings, and in these days, relatively expensive for building.
Limestone is a sedimentary rock. Like most other sedimentary rocks, is composed of mostly of small grains of skeletal fragments of marine organisms such as coral and mollusks. Other carbonate grains comprising Limestone are ooids, peloids, intraclasts, and extraclasts. These organisms secrete shells made of aragonite or calcite, and leave these shells behind when they die.
Acid rain is a significant problem to the preservation of artifacts made from this stone and (to a lesser extent) marble. Many limestone statues and building surfaces have suffered severe damage due to acid rain. Acid-based cleaning chemicals can also etch limestone, which should only be cleaned with a neutral or mild alkaline-based cleaner.
Limestone is readily available and relatively easy to cut into blocks or more elaborate carvings. In the United States, Indiana, most notably the Bloomington area, has long been a source of high quality quarried limestone, called Indiana limestone.
As the demand for limestone becomes apparent it has become directly proportional to the expense of excavation and tooling. Cast Stone has stepped up to become the best, affordable, and most convenient alternative to Limestone.