There are three main rock types - igneous, sedimentary, and metamorphic - that each form in different ways and impact land use differently. Igneous rock forms from cooling magma and is very hard, making it suitable for construction but limiting farming. Sedimentary rock like limestone forms from compressed sediments and produces karst landscapes that attract tourism; it is also used widely in construction. Metamorphic rock forms from the alteration of other rock types under heat and pressure and shares properties of igneous and sedimentary rocks, allowing uses like marble in construction.