Travertine is a sedimentary type of limestone which is formed in warm water spas that are rich in Calcium Carbonate. It is formed in a way that often air gets trapped within the rock which explains the porous structure of it. This is usually referred to holes in the body of the travertine. Travertine can be found in nature in various colours from the abundant cream-beige tones to exotic red, yellow, silver and pink variation depending on the minerals in the rock.
Limestone is a type of sedimentary rock that is formed of grains; most of the grains are formed from skeletal fragments of marine organism. Limestone can be composed of various amounts of Silica, Clay, Silt and Sand. Limestone can be found in various densities and colours in nature depending on the geology, soil structure and the pressure of its formation in nature.
Marble is regarded as a metamorphic rock. It has a crystalline structure that is mostly composed of minerals such as Calcite or Dolomite. Marble can be found in various colours in nature depending on the available minerals and pressure under which it is formed.
Granite is a common volcanic intrusive igneous rock. It is found in colours such as black, grey, pink or white depending on the minerals available. It is quite high in density when compared to other types of rock such as Travertine and Limestone. Granite is normally formed of 20% quartz and 65% Alkali feldspar by volume.