the
Mahanuddy " and were very fine but small. Later writers think the river
Gouel, of which Tavernier also wrote, to be identical with the North
Koel river, a tributary of the Sone, which in turn empties into the
Ganges to the north. Diamonds are found near Sumbulpur in a mixture of
red mud, sand and gravel, but the best yield is obtained from the north
branch of the Mahanadi where it is divided by Hira Khund, an island
four miles long. This branch of the river, in the dry season about the
end of March, is dammed up when the water is low, and when it is as
nearly dry as may be, the sands of the river bed are dug out, by men
who flock there in great numbers, and carried up onto the banks, where
the women wash them for diamonds. Some think that the southern branch
must also carry diamonds, but the greater volume of water and a swifter
current deter experiments. It appears also to be a settled conviction
of the natives that diamonds are only to be found on the north side of
the river.
There
are traditions of ancient diamond workings to the north and a little
east of Sumbulpur among the tributaries of the Brahmani river flowing
south, and the North Koel river running north to the Sone, and attempts
have been made to verify them, but a new set of suppositions only
resulted.
The
diamonds of the northern groups of mines occur in the Rewah group of
the Upper Vindyan series, and of the southern groups, in the
Banaganpilly of the Lower Vindyan section. Quartz, epidote, jasper,
limonite, chert and corundum are associated with the diamonds in the
Cuddapah and neighboring mines; epidote, ruby and sapphire in the
Bellary district; quartz, epidote, limonite,
