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• Title: Diamonds
• Author : William Crookes
• Release Date : January 06, 2020
• Genre: Crafts & Hobbies,Books,Lifestyle & Home,
• Pages : * pages
• Size : 9078 KB

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From the earliest times the diamond has fascinated mankind. It has been a perennial puzzle—one of the “riddles of the painful earth.” It is recorded in Sprat’s History of the Royal Society (1667) that among the questions sent by order of the Society to Sir Philiberto Vernatti, Resident in Batavia, was one inquiring “Whether Diamonds grow again after three or four years in the same places where they have been digged out?” The answer sent back was, “Never, or at least as the memory of man can attain to.”

In a lecture “On Diamonds,” fifty years ago,[1] Professor Maskelyne said, “The diamond

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 is a substance which transcends all others in certain properties to which it is indebted for its usefulness in the arts and its beauty as an ornament. Thus, on the one hand, it is the hardest substance found in nature or fashioned by art. Its reflecting power and refractive energy, on the other hand, exceed those of all other colourless bodies, while it yields to none in the perfection of its pellucidity.” He was constrained to add, “The formation of the diamond is an unsolved problem.”

Diamonds are found in widely separated parts of the globe. In the United States they have been found in Arkansas, where the work of testing the deposits is now going on steadily and quietly. The general geology and petrography of the area and the weathering of the peridotite are described in a paper read before the American Institute of Mining Engineers by Messrs. Kunz and Washington. In tests made with a diamond drill the peridotite was proved

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 to depths of 200 feet. The green and yellow grounds underlying the layer of black, sticky soil are found to extend down 40 feet in places, and are estimated to average 20 feet in depth over the area. The outcrop of the peridotite is estimated to cover about 40 acres, and may be larger. Some 540 diamonds have been found, with an aggregate of 200 carats. The largest stone weighs about 6·5 carats, though the average size compares favourably with the general run of most of the South African mines. There is a large proportion of white stones, many of which are free from flaws and are very brilliant. The genuineness of the occurrence of diamonds in their matrix is again proved, one stone having been found imbedded in the green ground at a depth of 15 feet. This peridotite has the form of a volcanic pipe, and therefore its outcrop is limited to one place.

In California authentic finds of diamonds are recorded in Butte County, especially at

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 Cherokee, above Orville. These diamonds, however, have come from alluvial deposits and have been found generally in washing for gold. As yet no authenticated discovery of diamond in its original matrix in California is recorded.

In Brazil the diamond industry has been increasing of late years, and the old mines in the Diamantina country are being worked by American capital and by the American methods which have proved so successful at De Beers. It is estimated that the annual value of the diamonds exported from Brazil amounts to over £800,000, but it is impossible to arrive at accurate figures owing to the large quantities smuggled out of the country to avoid payment of the export tax.

British Guiana produces a small quantity of diamonds, mostly, however, of small size. Between January and September, 1907, 1564 carats were exported.

Indian diamonds chiefly come from the

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 states of Panna, Charkhari, and Ajaigarh. In 1905 India exported 3059 carats, valued at £5160.

Cape Colony

It is a standing surprise to the watchful outsider how little attention is bestowed on some of our colonies. For instance, to the Cape Colony, comprising vast, varied, and productive regions, we have till recently manifested profound ignorance and consequent indifference. When the Cape Colony was first incorporated with the Empire, it was pronounced “a bauble, unworthy of thanks.” Yet before the Suez Canal and the Waghorn overland route to India, the Cape, as commanding our road to India, Australia, and China, had a special importance. Even now it presents an alternative route which under conceivable circumstances may be of capital moment.

The high grounds above Cape Town are rich in medicinal health-giving waters. The

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 districts where these springs occur are high-lying, free from malaria, and admirably adapted for the restoration of invalids. It needs only some distinguished power to set the fashion, some emperor, prince, or reigning beauty to take the baths and drink the waters, and the tide of tourists would carry prosperity to Aliwal North, Fraserburg, Cradock, and Fort Beaufort.

South Africa, as I shall endeavour to show in detail, is the most important source of diamonds on the earth, and ranks with Australia and California as one of the three great gold-yielding regions. But the wealth of South Africa is not only in its gold and diamonds. The province of Natal contains more coal than Britain ever owned before a single bucket had been raised, and the beds extend over the Orange River Colony, whilst valuable iron ores exist also in large quantities.

In the year 1896 I spent nearly a month at Kimberley. Mr. Gardner F. Williams,

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 General Manager of the De Beers Consolidated Mines, and the Managers of neighbouring mines, did their utmost to assist me in my inquiries and to ply me with valuable information. I had full access to all the workings, above and below ground, and was able to examine at leisure their stock and take extracts from their books.

Again, in the year 1905, I paid another visit to Kimberley as the guest of Mr. Gardner Williams on the occasion of the meeting of the British Association in South Africa.

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

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 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,

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 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

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 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.

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