METALLIC MINERAL: GOLD

GOLD

Economic Uses (i) Gold is a precious metal and till very
recently constituted the international standard of exchange. (ii) In alloy state with other metals, it is mostly used in ornamentation. (iii) The industrial uses of gold alloys are in dentistry, and in chemical plants, thermo-couples, watches, X-ray equipment, photography and some medicines.

Distribution in the World The greatest producer is South Africa, with major mines in the Witwatersrand, Odendaalrus and Lydenburg. Canada, Japan, the USA, Zimbabwe and Ghana also produce gold.

Distribution in India In India, the vein gold deposits are found in Kamataka, Andhra Pradesh, Assam, Bihar, Madhya Pradesh and Tamil Nadu while alluvial gold is mainly found in Bihar, Assam, Uttar Pradesh, Madhya Pradesh, Kerala, Punjab and Meghalaya.
The Kolar gold field in Karnataka has been the principal source of gold production in India since 1871 when mining first started. It has four productive mines­Nandydroog, Champion Reef, Mysore and Ooregaum. The Champion Reef mine is the deepest mine in the world. Th~ Oharwar schists on which the Kolar gold fields are situated run in a north-south direction for 80 km. 'However, the quartz veins bearing gold are confined to only a 6-7 km section near Marikuppan. The mineralising solutions re­sponsible for the development of the auriferous veins of South India were probably derived from the magma which gave rise to champion gneisses. The Kolar field mined by the Bharat Gold Mines Limited has always had the highest output in India, but it now faces closure.
In the Raichur district, the auriferous veins occur within the schistose rocks of Dharwarian age. There are six auriferous quartz reefs of which the Oakley reef is the main producer. It is worked by Hutti Gold Mines Company of Karnataka state. According to the Geological Survey of India, the reserves in both these fields are estimated at about 4.5 million tonnes with a total gold content of about
45,000 kg. In addition ore reserves of about 60,000 tonnes with 8.5 gm per tonne have been indicated in Budini area.

New fields have been found at Kempinkote (Hassan district), HOimali (Shimoga district), Siddarahalli (Chikmaglur district), Bellara (Chitradurg district) and Munglur (Gulbarga district).

In Andhra Pradesh, the Ramgiri field of Anantapur district is the main source of gold.