Diamonds in India - Part II

Kurnool District: A conglomerate bed about ten meters thick is found here. Diamonds occurred and still appear in the layers of this bed as small blue, green or yellow grains. The old kingdoms of Bijapur and Golconda had 38 diamond mines close to the Krishna river and other mines have also been reported by travelers. In general the mines were located in alluvium or river gravel, sedimentary rocks or archean crystalline rocks. The other areas where stones were found after rain were near the Banganapalle conglomerates. The layers were mines by sinking shafts of about 3-5 meters depth with galleries going along the seam. However, these diamonds were of poor quality being colored small and highly flowed.
Mines at Komarulu and Dhone have produced diamonds of medium quality but on the other hand the Lanjapolur stones were of a better grade. However the mines generated no revenue since 1813. These mines at Ramallakota and Varakaru produced stones of excellent quality, though of very small size. According to Tavernier, these stones were extracted from sand or the surrounding earth that occupied narrow veins in the rock. Near Virayapalle the diamonds yield was incredibly large, one carat of flawless and well formed gemstones from seven tones of ore. But since 1910 there has apparently been no output or even mining operations in this area.