 The Deccan was rich in minerals , though its soil was not as fertile as that of the Gangetic plains . The copper mines of Cudappah , Bellary , Chanda , <unk> , <unk> , Ahmadnagar , Bijapur and <unk> were an important source of income and played an important role in the economy . Diamonds were mined in Cudappah , Bellary , Kurnool and Golconda ; the capital Manyakheta and Devagiri were important diamond and jewellery trading centres . The leather industry and tanning flourished in Gujarat and some regions of northern Maharashtra . Mysore with its vast elephant herds was important for the ivory industry . 
