Assam is rich in mineral resources like Coal (320 Mn.T.), Limestone (703 Mn.T.), Iron Ore(11 Mn.T) and Granite(1 Bn. Cu. Mtrs) along many more resources like Fireclay, Lithomarge, Fuller’s Earth, Sillimanite and Glass Sand. The coal found in Assam has a high sulphur content and high volatile matter content, thereby reducing its cokeability. Limestone with reserves of about 500 million tonnes is another important resource and is available in various grades. The China clay available in the Karbi-Anglong district is a vital input for the ceramics industry and has already spawned a few small plants. Deposits of decorative stone like granite estimated to be more than a billion cubic meters are available in various shades and colours, which have a huge market potential locally and abroad. Opportunities based on minerals are Gasification & Liquefaction of Coal, De-Sulphurisation of Coal, Coal based Power Plant, Coal Bed Methane (CBM) Extraction, Exploration of Oil & Natural Gas and HDPE / LLDPE / Polypropylene based industries.
Assam has large reserves of coal too. The State is said to contain about 1200 million tonnes of coal reserves. The entire coal in this region is unique in the sense that it is highly volatile (36% – 42%), has low ash content (3% – 15%) and possesses high crackling index ( 10% – 29%).
Coal occurs mainly in Upper Assam districts of Tinsukia and Dibrugarh in the Makum and Dilli – Jeypore Coalfields. Small coal deposits occur sporadically in the Central Assam districts of Karbi Anglong and North Cachar Hills. The proved reserve of coal in this belt is about 340 million tonnes.
Assam possesses large deposits of granite which is mostly of pink & grey variety and found in Nagaon, Karbi Anglong, Kamrup & Goalpara districts. Some black variety of granite is also found sporadically in Goalpara district. Reserve of granite is estimated at 950 Million Cubic Metres.
The grey granite is extensively used in road making and as railway ballast. So far, it has hardly been exploited for decorative purposes and has great potential.
Limestone is an important mineral which is used in the manufacture of cement, as flux in iron and steel production, and as raw materials for chemical industries. There are now several cement factories which have come up in Assam due to the availability of high quality limestone in the region. Good quality cement grade limestone occur in the Central Assam districts of North Cachar Hills and Karbi Anglong where a total reserve of about 670 million tonnes is available for exploitation.
China Clay is mostly found in Upper Deopani, Silonijan, Sheelveta and Tengrajan areas of Karbi Anglong District. Both stacking and non stacking variety of China Clay is found here.
Sporadic occurrences of friable feldspathic quartzite found in Jiajuri, Chapanala, Borhola & Tanajuri in Nagaon & Karbi Anglong District are the main glass sand deposits. Inferred reserve of glass sand is about 10.50 million tonnes.
Iron Ore deposits are located at Chandardinga in Dhubri District and Lengupara in Goalpara District.
Promising deposits of sillimanite occurs in Unippilangso area of Karbi Anglong District.