Travertine is a type of porous malm stone with chemical origin, The sources of this stone is 450 million tons that some of them are unique because of quality, color and various designs such as Azar Shahr Travertine's have lots of customers in Iran and American markets. This stone is recognized as an expensive and luxurious stone by its fans. Iran is the only producer in the world. Mahllat white Travertine which has a source as much as 5/12 million tons, is one of the best slates to export . At present, there are 52 active Travertine mines in Iran, which 24 of them under A-S-IR.