Even so domestic roughs can meet only an infinitesimal portion of our annual requirements of roughs to feed the fledgling diamond cutting industry. This means that the country may remain dependent on imports of roughs in the foreseable future, unless there is discovery of some prolific mines in the country. There is at present only one tiny diamond mine in Panna, Madhya Pradesh.

The accompanying table shows how indigenous production of rough diamonds has gone up in recent years.

It may be interesting to note that India was the first country in the world to discover and process diamonds. For centuries it remained the only supplier of these sparklers to the world. Affluent people from everywhere turned to India when they wanted to get diamonds. India has givento the world several famous historic diamonds including the Koh-i-Noor. India's monopoly in this field continued until diamonds were discovered in Brazil (1725 AD) and later in South Africa (1866 AD).

By the time these new discoveries were made India's production of diamonds had started falling as it shallow diggings were getting exhausted.

Though the availability of diamonds from alluvial diggings implied the presence of some diamond pipes lying buried somewhere under overburden. However little serious effort was made in that direction in the past. Diamond exploration and mining was a state subject and the private sector was denied entry into this field. It is only recently that the policy has been relaxed and diamond exploration and mining might get a fillip in the coming years.

The resurgence of modern diamond cutting industry in India since the early '60s is based almost entirely on imported rough diamonds. The Exim policy of the Union government is aimed at facilitating imports of roughs andpromoting exports of polished diamonds. This policy has been quite successful.

Meanwhile, the Geological Survey of India (GSI) is concentrating its regional search for kimberlites in basal Chhatisgarh formation and in the surrounding Saraipalli area. Ground evaluations of aerogeophysical anomalies in parts of Raipur district and adjoining districts of Orissa are continuing to locate mineral targets including kimberlites. In Maharashtra a multidisciplinary programme of search for kimberlites and lamproites was taken up last year in Chandrapur, Nanded and Gadchiroli districts.

In Andhra Pradesh two investigations were undertaken last year for search of new kimberlite bodies in the granite greenstone belts in central segment of Vajrakarur kimberlite field, Anantapur district and Closepet granite in the Kalyandurg area, Anantapur district.

Three new kimberlite pipes (KL - 1, 2, 3) have been identified within the Closepet granite in Kalyandurg area. A microdiamond has been found from KL-2 body.

Bulksamples from Anumpalle (P-10), Dibasanipalle (P-11) and Golapalle (CC -4) kimberlite bodies have been processed.

So far 24 diamonds weighing 3.58 carats have been recovered by processing 659 tonnes of material from the Anumpalle body. A total of 225 tonnes of kimberlite material from Dibbasalipalle body has been processed and two diamonds weighing 2.15 carats have been recovered. The Golapalle body has produced 15 diamonds weighing 2.28 carats from the processing of 88 tonnes of material.

In Orissa, search for kimberlite/lamproite pipes in Indravati basin, Koraput and Nawarangpur district has led to the identification of a number of prominent linements and a zone of high magnetic permeability near the northern margin of the basin.