DIAMOND: OCCURRENCE IN SOUTH AFRICA 185 



being at the present day the centre of the diamond-washing industry. In addition, diamonds 

 have been found in small numbers further up the river at Hebron, and even as far as 

 Bloemhof and Christiana in the Transvaal ; also in the opposite direction, at the junction of 

 the Vaal with the Orange River. A few diamonds have also been found in the Orange 

 River, between its confluence with the Vaal and Hopetown, as well as in some of the tribu- 

 taries of the Vaal, notably the Modder and the Vet. The yield in all these places was, 

 however, so poor that the workings were soon all abandoned except the portion of the Vaal 

 River mentioned above, and a stretch of its valley, parallel to the same portion of the river, 

 and measuring fifty miles in a straight line, or seventy-two following the windings of the 

 nver. At the present day whole series of mines even in this region are practically deserted, 

 the workers having left the river for the far richer dry diggings of Kiraberley. The production 

 of the river diggings up to 1871 was of some importance, but is now quite insignificant; in 

 spite of the poorness of the yield, and the miserable conditions under which they have to 

 work, a small number of a certain peculiar class of diamond-miners still cling tenaciously to 

 their holdings in the hope no doubt of better days coming. Counting both black and white 

 men, their number for many years probably did not exceed two or three hundred ; they work 

 singly or in twos or threes, not in large companies, and are most frequently to be seen in the 

 neighbourhood of New Gong-Gong, Waldeck's Plant, and Newkerke. The amalgamation 

 of the " dry diggings ■" to form the De Beers Consolidated Mines, has had the effect of 

 increasing the number of river diggers, it being estimated that there are now 1000 of them, 

 exclusive of native workers. Companies have been formed with the object of working the 

 deeper beds of river sand, but have met with little success. The river-diggings, on account 

 of their poor yield, are known as " poor men's diggings.'' 



The bed of the Vaal is strewn with blocks of basalt, often amygdaloidal in character, 

 and with other rocks which are probably of metamorphic origin. These blocks are usually 

 of considerable size, and have been wa?hed down from the sides of the valley and from the 

 surrounding hills; between them lies a loose material consisting of gravel, sand, and mud, 

 and it is in this that the diamonds are found. The whole deposit, which varies in thickness 

 up to 40 feet, rests on basalt, this rock being in situ, and is here and there scooped out to 

 form deep hollows, known as pot-holes or " giant's-kettles," similar to those found in the beds 

 of the diamond-bearing rivers of Brazil, which have been worn out by the continued whirling 

 of pebbles in the eddies of the stream. The diamond-bearing debris accumulates in these 

 depressions, which often yield a rich harvest to the finder. 



The search for diamonds was at first confined to the bed of the river, but it was soon 

 discovered that the sands and gravels of the river-terraces were as rich or richer than the 

 river-bed, so that these also came to be worked. The terraces and their workings are usually 

 only a few yards above the present high-water level, but one or two are 200 feet above this 

 level. The workings in the river- terraces are easier to manage and more secure than those 

 in the river-bed, since the latter are liable to be flooded, and thus considerably damaged ; 

 it has, therefore, been proposed in recent times that the stream should be diverted into 

 another channel, but this scheme has never yet been carried out. 



The diamonds found in this sandy clay are, as a rule, distinctly water-worn, though not 

 of course to the extent of the other pebbles and sand grains which accompany them. These 

 accompanying pebbles consist of various minerals, the diffei'ent varieties of quartz (agate, 

 jasper, silicified wood, &c.), which have all travelled down from the upper courses of the 

 river, being especially abundant. Pebbles of the rocks which occur in situ in the neighbour- 

 hood are present in large numbers in these alluvial deposits. The minerals which are 

 associated with the diamond in the dry diggings are less abundant, but small fragments of 



