Diamond resource in Andhra Pradesh has just got bigger with Geological Survey of India finding new imberlite/lamproite regions

Syed Akbar
Hyderabad, July 18: The diamond resource in Andhra Pradesh has just got bigger with the Geological Survey of India finding new areas for potential exploration in Kadapa, Krishna and Mahbubnagar districts.
In the last 15 years the diamond resource in the State grew by 350 times to 20 lakh carats, as teams from the GSI, NGRI and other organisations studied new areas for the presence of diamonds.
According to the Detailed Information Dossier (DID) on diamonds prepared by the GSI, the diamond potentiality identified in Andhra Pradesh was 5465 carats on April 1, 1995. It went up to 18.22 lakh
carats by April 1, 2005.
The diamond resource in the State was 19 lakh carats in 2009 and the latest estimates put it as about 20 lakh. This in other words means an increase in diamond potentiality in Andhra Pradesh by as much as 350
times in just over a decade, thanks to continuous search for the precious stone.
"The potentiality in Andhra Pradesh has increased with kimberlite/lamproite, which point to the presence of diamonds, being identified in new places. Not all kimberlite/lamproite yield diamonds, but they are the places where we look for diamonds. More number of kimberlite pipes means more potentiality of diamonds," said MS Jairam, director (monitoring), Geological Survey of India.
The GSI has now identified newer areas for diamond studies as earlier findings were quite encouraging. Though the focus will be on Kadapa, Krishna and Mahbubnagar, further studies will also be conducted in
Anantapur, Guntur and Kurnool districts.
It has also identified new kimberlite pipes in Kadapa and Mahbubnagar. The areas abutting the Krishna river course in Krishna district and those in the upstream of its tributaries, Munneru and Paleru, in Khammam district will be explored.
Areas hither to not explored, not known for diamonds or kimberlites and capped by the black soil will also be targeted for search. They include the Nallamalai Fold Belt, area between the north eastern corner
of the Cuddapah Basin and the Pakhal Basin, particularly occupied by the Munneru, Dindi and the Paleru river basins. The discovery of new kimberlites may lead to opening of new mines by 2015.
The GIS is now busy updating the DID data and once it is completed, it will submit the report to the Central government. "It is apparent that a number of kimberlites/lamproites exist and lie undetected in the soil covered areas south, west and north of the Cuddapah Basin and within the basin itself. We will know the exact quantum of diamond resources in Andhra Pradesh after we get the latest report from the Indian Bureau of Mines," he added.
Of the estimated 45.80 lakh carats in the country, Andhra Pradesh accounts for a little over 40 per cent of diamond resources. "The GIS has carried out studies in potential areas, besides identifying newer ones for research. Depending on the economic feasibility, the National Minerals Development Corporation will take up mining. As scientists, our duty is to find newer sources of minerals," Jairam said.
Though Andhra Pradesh stands first in terms of hidden diamond wealth, there has been no mining activity in modern times. All the diamonds that brought fame to the State (Golconda mines) were mined more than a century ago, though occasionally diamonds were found by accident and in test mining. A dozen of the 20 world famous diamonds including Kohinoor, Nizam, Hope and Darya-e-Noor, were mined in the Krishna river.