detritus
derived from the disintegration of the Vindhyan beds. The workings are
also distributed accordingly— some on removing the undisturbed
conglomerate and others to recover stones included in the more recently
distributed detritus. When the conglomerate is covered by younger
Vindhyan rocks, it is reached by workings, which are often, but not
always, deep. Such workings are known as 'direct workings'. In some
places the overlying rocks have been removed by weathering agents, and
the conglomerate thus exposed affords shallow workings. In the case of
conglomerate removed and deposited in river* valleys, the stones are
obtained by superficial, shallow and deep workings, which come under
alluvial workings.
The following are the mining areas at present working: (1) Shahidan area
forms the best centre in the Panna State, and has been working
regularly since 1916. The size and quality of stones are better than in
other mines. Due to unsystematic working, the mines present a
confusing spectacle. Water often runs from old workings, rush into
newer ones and spoil the mines. (2) Panna group—Banipur and Bhavanipur—the latter has been working from 1916 to the present day. It occurs in redistributed material of the mvdda. Undecomposed material may also be present. (3) Baghri group of mines—The Itwa field—it is next in importance to the Shahidan diamond
field, arid is 13 miles N.E. of Panna. Workings are now in alluvium,
but many years ago mining was in a regular conglomerate bed occurring
below a sandstone. At a depth of 20-40 ft. from the surface a
diamondiferous gravel bed is also present. (4) Majgawan agglomerate tuff. These
mines lie to the west and southwest of Panna. The diamond occurs in a
green mud and it is said that diamonds became more abundant as a shaft
descends. The rook, on careful examination, has been found to be an
agglomeratic tuff. The greenish tuff occurs at a depth of 105 ft. from
the surface in the particular part where the borehole was
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