Underground waters including solved carbon-dioxide within carries calcium carbonate (CaCO3) by dissolving it. By means of the water appearing in non-pressurized environment and the loss of carbon dioxide, dissolved calcium carbonate in the water falls down to the surface of the rocks. This will create travertine by the time of progress.
Travertine is a building material used together with the marble. There are travertine mines in a lot of regions of Iran such as Azarshahr , Isfahan, Ardabil ,.. . Manufactured material is used in domestic market as block, debris or sized, honed and polished travertine after being processed in factories or exported.