26 Anniversary Address. 



whicli it is associated. It appeared to Mr. Medlicott to be 

 somewhat of a puzzle where to place the conglomerate among 

 the regular beds, and he considers the ferruginous element 

 to be subsequent to the deposition. The beds thin out and thicken 

 remarkably. The natives seem to have ascertained the limits of 

 the diamond area, owing probably to the beds dying out. The 

 base of the hills has not been tried. 



As to the origin of the Diamond, he does not think the stratum 

 in which it is found is its native bed. He saw no diamonds 

 in situ, but, from what he learned of the labourers, " the diamonds 

 came as pehhles with the rest^ Quartz pebbles of any kind are 

 rare. The most prominent pebbles are subangular red and white 

 shale, and of Avhat Franklin calls " green quartz," which is 

 elsewhere described by Mr. Medlicott as " glazed or semi-vitrified 

 sandstone." Pieces of the calcareo-siliceous bottom rock, of the 

 size of boulders, occur also. One of the workmen confirmed his 

 opinion, that the occurrence of these pebbles indicated the 

 presence of the gem, and that " they theinselves contained diamonds, 

 and were hrohen up" as ore or, rather, as gangue. 



In a section just north of the mines, twenty feet of regular 

 beds of cherty and compact limestone rest on fifty feet of 

 alternating sandstone and shale, based on rich sienite ; the cherty 

 and jaspery condition of some of the more vitrified beds is shown 

 by another section to be due to a "modifying influence." It is 

 supposed that these beds are the sources of the boulders in the 

 diamond conglomerate. 



Besides these diggings, the great majority are said to be 

 alluvial. 



On the Rewa escarpment, in the Vindhyan region, they are at 

 the heads of valleys descending from the plateau, where kunkery 

 and lateritic clays pass into a mixture of clay, gravel, and 

 boulders, increasing to great angular blocks of sandstone, between 

 which the diamonds are found. Diggings occur also on the 

 slopes. In one place men were seen removing twelve feet of 

 dark brown clayey sand to get at the boulder bed, the base of 

 which is richest. 



" The limited distribution of the transported diamonds was 

 more puzzling" to Mr: Medlicott than that of the rock. He 

 thinks there are indications beyond the area that is worked. 



