The origin of pottery in India can be traced back to the neolithic age. Coarse handmade pottery in various colors such as red, orange, brown, black and cream mainly consisted of different types of bowls, jars, vessels, etc. Harrappan and Mohanjodaro cultures heralded the age of wheel-made pottery. These were characterized by well-burnt black painted red wares. The phase of glazed pottery started in the 12th century AD, when Muslim rulers encouraged potters from the Middle East to settle in India. Glazed pottery of Persian models with Indian designs, dating back to the Sultanate period has been found in Gujarat. The terra-cotta objects are made by hand or on the wheel, and firing them in an open oven. The surface is rubbed and polished, with a wood or stones while it is still wet. The first pottery unit run in India was by Sir S Deb, in Calcutta. It established the success of high-class pottery made out of local clay. Porcelain factories were set up in Gwalior and Calcutta in first decade of 20th century. Today, the pottery industry is run on both cottage and modern lines. Hundreds of small and big factories all over the country keep this age-old tradition alive. Apart from commercial and sociological implications, pottery in India has deep religious significance. For instance, if no image of a deity is available, a water-pitcher is worshipped as 'mangalghat' (good omen). The translucent blue pottery of Delhi and Jaipur, with its unique arabesque patterns, has lent a touch of grandeur to the art of pottery. Functional items like flowerpots or Diwali lamps too are a part of this fascinating tradition.