embedding
rolled pebbles of quartz, chert, and jasper; claystone porphyry, with
crystals of felspar ; blue jasper, veined with oxide of iron ; coarse
red jasper, and quartz crystals. Some of these pebbles have evidently
been transported from the adjacent hills, but the porphyritic and
felspathic pebbles must have travelled a much greater distance. Near
the base of the hills the cotton soil is covered with red gritty earth,
arising from the disintegration of the sandstone rock.
The
process of mining consists merely in digging out the rolled pebbles and
gravel, and carrying them to small square reservoirs raised on mounds,
having their bottom paved with stones, and washing them carefully. At
the foot of the mound is a clear space surrounded by heaps of refuse,
where the washed gravel is again carefully spread out and examined in
presence of the diamond contractors ; the diamonds are easily
recognized in the moist state by their peculiar lustre. These mines are
let out by the Government to native contractors, who gave me the
following information on the spot. In 1834 the mines proved profitable,
but in the following year the miners lost a considerable sum. The sum
paid to Government by them for the privilege of mining a piece of
ground 100 yards long by 50 broad, for four months, is 200* rupees.
Dry
weather is selected to carry on operations to avoid the inconvenience
and expense of draining. In former days all the diamonds produced were
carried for sale to Golconda. In those times very large diamonds were
found; but subsequent to British ascendency—which according to the
superstitious natives is by no means pleasing to the tutelary deities
of the mines—few of any
*
In 1840, the contract rose to about 250 rupees. When a diamond of more
than a gold pagoda in weight (= 52.56 grains at Madras) is found it is
sold by public auction, and one-third of the proceeds goes to
Government, the remainder to the mining contractor.
