_Iron._--In purity of ore, and in antiquity of working, the iron deposits of India probably rank first in the world. They are to be found in every part of the country, from the northern mountains of Assam and Kumaun to the extreme south of the Madras Presidency. Wherever there are hills, iron is found and worked to a greater or less extent. The indigenous methods of smelting the ore, which are everywhere the same, and have been handed down unchanged through countless generations, yield a metal of the finest quality in a form well suited to native wants. But they require an extravagant supply of charcoal; and even with the cheapness of native labour the product cannot compete in price with imported iron from England. European enterprise, attracted by the richness of the ore and the low rate of wages, has repeatedly tried to establish iron-works on a large scale; but hitherto every one of these attempts has ended in failure with the exception of the iron-works at Barrakur in Bengal, first started in 1865, which after many years of struggle seem to have turned the corner of success. The principal sources of iron-stone at present are the Madras ores, chiefly at Salem, the Chanda ores in the Central Provinces, and the ores obtained at and near Raniganj in Bengal.
_Petroleum._--The great oilfields of the Indian empire are in Burma, which supplies 98% of the total output. Of the remainder nearly all comes from Assam. In both provinces the growth of the yield has been very great, the total output in 1901 being six times as large as in 1892; but even so it has failed to keep pace with the demand. A regular service of steamers carries oil in bulk from Rangoon to Calcutta, and now Burmese oil competes with the Russian product, which had already driven the dearer American oil from the market (see BURMA).
_Other Ores._--Manganese ore is found in very large quantities on a tract on the Madras coast about midway between Calcutta and Madras. Most of the ore goes to Great Britain. There are also valuable deposits of manganese in the Central Provinces and, it is believed, in Burma. The export of manganese, which had been only about ten years in existence in 1905-1906, amounted then to 316,694 tons, with a value of £250,000. Mica has long been obtained in Bengal, chiefly in the Hazaribagh district, and there is a ruby-coloured variety which is held in great estimation. In Madras also a mica industry has recently grown up. Tin is found in the Tavoy and Mergui districts of Lower Burma, and has for many years been worked in an unprogressive manner chiefly by Chinese labour. In 1900 tin of good quality was found in the Southern Shan States. Copper ore is found in many tracts throughout India, plumbago in Madras, and corundum in southern India.