River Washings
Besides the matrix mines, where the stones are found in pipes supposed to be of volcanic origin, the alluvial deposits on the Vaal River are of considerable importance. The terraces and gravels along the Vaal River for about 200 miles have been worked for diamonds, the deposits sometimes extending several miles on each side of the river, and varying from a few inches to 40 or 50 feet in thickness. The diamonds are found almost everywhere through the gravel deposit.
Before describing the present mode of diamond extraction followed in the important mines, I will commence with these “River Washings,” where, in their primitive simplicity, can be seen the modes of work and the simple machinery long since discarded in the large centres of the industry. The drift or so-called “river washings” present a very interesting phase of diamond industry. The work is carried on in the primitive fashion adopted in the early days of diamond discovery, every man working on his own little claim, assisted by a few natives, and employing primitive machinery ([Fig. 1]). The chief centre of the Vaal River washings is about 30 miles to the north-west of Kimberley, at a place called Klipdam No. 2. There was originally a Klipdam a few miles further, and here the miners congregated, but the exhaustion of their claims made them migrate to others not far off and reported to be richer. Here, accordingly, they re-erected their iron houses and called it Klipdam No. 2.
It is a mistake to speak of “river washings.” The diamantiferous deposits are not special to the old or recent river bed, but appear to be alluvial deposits spread over a large tract of country by the agency of water, which at some period of time subsequent to the filling up of the volcanic pipes planed off projecting kopjes from the surface of the country and scattered the debris broadcast over the land to the north-west of Kimberley. The larger diamonds and other heavy minerals would naturally seek the lowest places, corresponding with the river bed, past and present. The fact that no diamonds are found in the alluvial deposits near Kimberley may perhaps be explained by supposing that the first rush was sufficiently strong to carry the debris past without deposition, and that deposition occurred when the stream slackened speed. At Klipdam No. 2 the diamantiferous earth is remarkably like river gravel, of a strong red colour—quite different from the Kimberley blue ground—and forms a layer from 1 to 8 feet thick, lying over a “hard pan” of amygdaloidal trap, the melaphyre of the Kimberley mines.
FIG. 1. RIVER WASHINGS AT KLIPDAM.
FIG. 2. PLAN OF THE KIMBERLEY DIAMOND MINES.
To face p. 10.
When I was at Klipdam the miners had congregated at a spot called “New Rush,” where some good finds of diamonds had been reported. The gravel is dug and put into a machine resembling the gold miner’s dolly, where it is rocked and stirred by rakes, with a current of water flowing over it. Here all the fine stuff is washed away and a rough kind of concentration effected. The residual gravel is put on a table and sorted for diamonds—an operation performed by the master. At one of the claims where work was proceeding vigorously I asked the proprietor to let me be present at the sorting out, as I should like to see river diamonds. He willingly consented, but no diamonds were to be found. On my expressing regret, he said he had not seen a diamond for a fortnight! I remarked that the prospect was rather a poor one, but he told me that a fortnight before he picked out one worth £300, “and that,” he said, “will pay for several weeks’ wages of my boys.” This is the kind of speculative gambling that goes on at the river diggings. The miner may toil fruitlessly for months, and then come across a pocket of stones, where they have been swept by some eddy, by which he will net several thousands. Diamonds from the “river washings” are of all kinds, as if contributed by every mine in the neighbourhood. They are much rolled and etched, and contain a good proportion of first-class stones; they are of very good quality, as if only the better and larger stones had survived the ordeal of knocking about. Diamonds from the drift fetch about 40 per cent more than those from Kimberley; taking the yield of the Kimberley and De Beers mines as worth all round, large and small, 26s. 6d. a carat, those from the drift are worth 40s.
As a rule the better class of natives—the Zulus, Matabeles, Basutos, and Bechuanas—when well treated, are very honest and loyal to their masters. An amusing instance of the devotion of a Zulu came to my knowledge at Klipdam. He had been superintending a gang of natives on a small claim at the river washings. It yielded but few stones, and the owner—my informant—sold the claim, handing over the plant and small staff, our friend the Zulu remaining to look after the business till the new owner took possession. In the course of a few months the purchaser became dissatisfied with his bargain, not a single diamond having turned up since the transfer. One night the Zulu came to his old master in a mysterious manner, and laying a handful of diamonds on the table, said, “There, Baas, are your diamonds; I was not going to let the new man have any of them!”
[CHAPTER II]
KIMBERLEY AND ITS DIAMOND MINES
The famous diamond mines in the neighbourhood are Kimberley, De Beers, Dutoitspan, Bultfontein, and Wesselton ([Fig. 2]). They are situated in latitude 28° 43´ South and longitude 24° 46´ East. Kimberley is practically in the centre of the present diamond-producing area. Besides these mines others of some importance of the Orange River Colony are known as Jaggersfontein and Koffyfontein, Lace, and Monastery, besides two new mines, the Roberts-Victor and the Voorspoed.
The areas of the mines are:
| Kimberley | 33 acres |
| De Beers | 22 acres |
| Dutoitspan | 45 acres |
| Bultfontein | 36 acres |
In 1907 the total number of carats raised from these mines was more than two million and a half, the sales of which realised £6,452,597.
The most important mine outside the Kimberley group is the new Premier Mine, about 20 miles West-North-West of Pretoria, where the famous Cullinan diamond was found.
Other diamond mines are the Frank Smith, Wesselton, the Kamfersdam, the Kimberley West, the Newlands, and the Leicester Mine.
The surface of the country round Kimberley is covered with a ferruginous red, adhesive, sandy soil, which makes horse traffic very heavy. Below the red soil is a basalt, much decomposed and highly ferruginous, from 20 to 90 feet thick, and lower still from 200 to 250 feet of black slaty shale containing carbon and iron pyrites. These are known as the Kimberley shales; they are very combustible, and in a part of the De Beers Mine where they were accidentally fired they smouldered for over eighteen months. Then follows a bed of conglomerate about 10 feet thick, and below the conglomerate about 400 feet of a hard, compact rock of an olive colour, called “Melaphyre,” or olivine diabase. Below the melaphyre is a hard quartzite about 400 feet thick. The strata are almost horizontal, dipping slightly to the north; in places they are distorted and broken through by protruding dykes of trap. There is no water nearer than the Vaal River, about 14 miles away, and formerly the miners were dependent on rain-water and a few springs and pools. Now, however, a constant and abundant supply of excellent water is served to the town, whilst good brick houses, with gardens and orchards, spring up on all sides. To mark the rate of progress, Kimberley has an excellent club and one of the best public libraries in South Africa. Parts of the town, affectionately called “the camp” by the older inhabitants, are not beyond the galvanised iron stage, and the general appearance is unlovely and depressing. Reunert reckons that over a million trees have been cut down to supply timber for the mines, and the whole country within a radius of 100 miles has been denuded of wood with the most injurious effects on the climate. The extreme dryness of the air, and the absence of trees to break the force of the wind and temper the heat of the sun, probably account for the dust storms so frequent in summer. The temperature in the day frequently rises to 100° in the shade, but in so dry a climate this is not unpleasant, and I felt less oppressed by this heat than I did in London the previous September. Moreover, in Kimberley, owing to the high altitude, the nights are always cool.
The approach to Kimberley is deadly dull. The country is almost treeless, and the bare veldt stretches its level length, relieved only by distant hills on the horizon.