Natural stone is a collective name for an array of different types of stone, found and quarried throughout the world. The appearance and the characteristics of natural stone are determined by the manner in which the stone was formed; by rivers, volcanoes, tectonic folding.
Each natural stone is unique, because no two places on earth have precisely the same geological composition or experience precisely the same geological forces. This means that natural stone of the same type can also differ widely.
Natural stone is most commonly divided into several large groups, with granite, marble, limestone, travertine, basalt, slate and onyx considered the most important but with the likes of sandstone and soapstone being also as important.