The Diamond Diggings.

Thames Star, Volume XII, Issue 3927, 30 July 1881, Page 1

The Diamond Diggings.

[FBOM THE SCOTSMAN.] Although the chemist has at length succeeded in producing the diamond, it is in the last degree improbable that laboratory diamonds will erer compete with the natural stones. Mr Hannay's suecessful experiments made evident the enor^ mous difficulties^ in the way of securing the conditions tiecessary for their artificial production ; anji from the great rarity of diamonds in nature, it may be gathered that the requisite conditions for their natural formation have also been of comparatively rare occurrence. The diamond supply is, and probably always has been, very limited; but a little goes a great way with a material which, when once found, is too valuable to be readily lost sight of, and which is as nearly as possible indestructible. Being merely a peculiar form of carbon, fire will no doubt consume it, but the intensity of heat required to consume it into coke, or to dissipate it altogether, is nob likely to be met with accidentally. Diamonds which passed through the great fire at Hamburg were as brilliant as ever after repoiishing. The precious metals literally perish with the using, but tear and wear have no appreciable effeut on the diamond. Consequently, there are stoues whose histories are perfectly well known for centuries back, such as the Koh-i-noor of the British Crown, which, according to Hindoo legend, was worn 5000 years ago by one of their national heroes. Thus, also, it is, that India, which for a centurj past ha's almost ceased to produce diamonds, is, through its accumulations of past ages, probably the chief diamond-possessing country of the world. A few diamonds have been found in Europe among the alluvial gold deposits of the Ural Mountains, the largest weighing under 8 carats ; nqt more than have been found in Australia. Borneo hai yielded a few, and among these the largest; known ■diamond—belonging to the Rajah of Mattan—which is of the purest water, and weighs 367 carats. The world's stock of these gems has, however, been obtained mainly from three localities, each of which has in succession formed the chief source. Until a century and a half ago, they almost all came from India, where, in the neighbourhood of Qolconda —the name of a fortress where the stones were stored, 60,000 persons were employed two centuries ago in diamond digging; aud so abundant were diamonds that Sultan Mahmoud is said to have left in his treasury at his death 400 pounds' weight of thom. They occur in a kind of pudding stone, encrusted so as not to be readily distinguished ; the diamondseekers accordingly break up the stone, and wash it in basins, spread out the resulting gravel to dry, when the gems are recognised as they sparkle in the sun. The diamondiferous districts of India were gradually getting exhausted whenthe discovery of similar depos 'U in Brazil was made. The stones were found by the Natives in searching for gold, bat not knowing what'they were, they used (hem as counters in card playing, until a Brazilian who had been in the East Indies recognised their true nature. A rush of emigrants then followed, and the increased production of diamonds which ensued had the effect at the time of reducing their value one-half. The Brazilian diamonds are found in a conglomerate rock, cou* sisting of pebbles of quartz and jasper,, cemented together by a ferruginous sand, and having grains of gold disseminated through it. The true matrix of the

diamond however, is believed to be a sandstonej^ttotsrii as It,a(B.Qliimite,_and , times found very flexible,.the disintegration of which ;)iaß; supplied the conglomerate with diamonds. During the dry season in Brazil, certain of the rivers are diverted from their channels, while the'diamondliferous gravels are removed fromtheir natural beds and placed in , .heaps. The contents of these are afterwards washed iu troughs, and the diamonds picked out by the negro slaves, th^e fortunate finder of one weighing at leak 17| carats being rewarded by receiving.his liberty. The largest known Brazilian diamond—found by a negro in 1853—weighed 254 carats. It has since been cut, and has thus lost fully half of. its weight. The-stones now found do not weigh on an average more than 1 carat, and, owing to their growing unproductive ness, few of the Brazilian.diamond fields are now worked. The third diamond field, and that which now yields the chief supply, is the South African, an interesting account of which was given by Mr R. W". Murray, a Cape colonist, at a recent meeting of the London Society of Arts. There, as in Brazil, diamonds were being handled by people who had not the remotest idea of their ralue. The child of a Boer on the banks of the Vaal River, was playing with some pretty pebbles which she had picked up, when one of them by its lustre attracted the attention of a passing trader. Having confided to the girl's father his belief that the pebble was a diamond, the trader agreed to halve the profit with him should his surmise prove correct. The Qneen's jewellers pronounced it a diamond of 22J carats; worth £500, and at this price it was purchased by Sir Philip Woodhouse, at that time Governor of Cape Colony. The receipt of half this sum by the parent Boer called to his recollection the fact that he had seen a similar stone in the possession of a native, and seeking him out, he gave him, says Mr Murray, nearly all he possessed—soo sheep, horses, &c;, —in exchange for this pebble. It proved to be a diamond of 83 carats, and: he obtained for it £11,200. This is the stone now in the possession of the Countess of Dudley, and known as the "Star of South Africa." Such finds" naturally produced the wildest excitement throughout South Africa, and led to a rush of diamondseekers, first from the surrounding colonies and soon from all parts of the world. The early parties had no idea of digging for diamonds ; they sought for them on the surface along the ridges of the hills, and succeeded tolerably well. An Australian gold digger arriving on the scene inaugurated the " cradling " method employed in California and Australia for the separation of the gold in alluvial deposits. The diamondiferous soil, consisting of drift and pebbles of agate, jasper, and cornelian, with here and there a diamond, was dug out, and after thorough washing, the gems were readily picked from the gravel. In 1870, within a year after the.first rush, there were 1000 cradles at work on the banks of the Vaal. These were known as the wet or river diggings, but after a time they were- abandoned for the more productive dry diggings. These were too far from the river to render tbe washing of the diamondiferous material possible, nor was it needed, owing to the light sandy nature of the soil. The digger had only to pass the stuff" through a couple of sieves over a serting table, when the sorter was able to pick out whatever diamonds it might contain. The first possessors of those dry: •? claims ■" dealt only with the loose upper soil, sinking their pit's only a depth of three or four feet. Their sue cessors, however, finding the surface diggings exhausted, tested the rocky stratum .beneath—" a kind of looselypacked rock, blus in colour, and bard to crumble," which the early diggers had regarded as putting a period to their hopes of diamonds deeper down—when they were rewarded by finding that it contained more and finer diamonds than even the best surface deposits. Diamond mining was accordingly begun, and with it came the, need of steam machinery and other expensive plant, necessitating the employ-, ment of a large amount of capital and the formation of mining companies. Mines have now been sunk to a depth of 400ft., in the course of which reefs, not diamond.bearino, have had to be cut through, and powerful, pumps to be employed to prevent flooding. Those diamond-bearing areas are circular in shape, and forn> what are known as "pipes." They are filled with intrusive rocks which have been forced up by volcanic agency almost perpendicularly through the surrounding horizontal strata of shals, and through which, as wejl as through a colcareous tufa usually found on the upper parts of the "pipe," the diamonds are disseminated. Owing to the fact that a large portion of the diamonds consist of fragments, it is generally thought that " pipe " rock is not the true matrix of the diamonds, but that it has merely been the agent- in bringing them to the surface from some lower deposit. The richest of the mines is that of Kimberley, which has an area of about seven acres. Its original possessor! sold the estate, of which it was a small part, for £6000, and it soon yielded to its purchasers from £20,000 to £25,000 per annum in rents. The .Kimberly mines contains about £400 claims, which four years ago were worth three-quarters of a million sterling ; in August last, according to Mr Murray, they could not be purchased for three and a half millions. There is no means of accurately ascertaining the value of the diamond production of South Africa, but the importance of the new industry may be gathered From the fact that the value of the diamonds sent through the Post Office in 1879amountcd to £3,685,000. Sincci; the finding of the "Star of South Africa" much larger diamonds have turned up, notably one found in 1872, weighing 288| caraits, from which it is believed that a brilliant weighing halt, as much again as the Eoh-i noor may be cut, and the still larger one .found by Mr Rhodes, recently exhibited to the Queen. Unfortunately, the diamonds of South Africa are not all of purest water, the majority of them being straw-tinted, and therefore of considerably less value than colourless.specimens. Those diamond discoveries are having an epormous influence in the development of South Africa, which, previous to 1870, was in a decidedly languishing condition, Proof of this is seen in the. fact that the imports for the Cape Cojony, which in 1869. .were, under two millions sterling, had risen in 1879 to more than seven millions. Griqualand West, in which the principal fields are, now contains several important towns, and a large and enterprising, population, rich enough, in the ca>e ,of to bring their water supply from a distance of fourteen miles. A trunk railway is about to be constructed to connect the diamond regiou vrifh Cape Colony; which willhdve the further efi'ect

of developing the other resources of a rich but hitherto • inaccessable region. The discovery would seem also to have benefitted the natives by finding employment for them at remunerative wages, and by bringing them under civilising influences. Most of the manual labour at the mines is performed by natives, of whom 640.000 have been registered during the past seven years as servants of claim holders. These earn 12s per week besides their food, and in the great majority of cases the discipline of steady work, has according to Mr Murray, transformed those (at first) lean, naked, and stupid natives, into welldressed, well fed, and, on the whole, well behaved workmen, with sufficient intelligence to see to the building of schools and churthes for themselves,