Diamond Mines Of South Africa Continued
( Originally Published 1911 )
FROM the discovery of diamonds in Africa until 1884, there are no records by which one may know with certainty what the production was, either in weight or in value. The probability is that up to and including 1873, it was not over one million carats. From 1874 to 1883, however, there was a very large increase. The output ranged probably from a million carats in 1874 to something over two million carats in 1883 and possibly three million carats each for the years 1881 and 1882. From 1884, official records were kept of the exports from Cape Town to London. These show an average of close on to three million carats per annum for the twenty years including 1903, at an average yearly value of nearly twenty-six and three-quarter millions of dollars, the average value per carat being lowest in 1888 at $5.095 and highest in 1902 at $9.922.
Large percentages in the yield of diamonds were re-ported in the early days, of the Kimberley mine especially, and undoubtedly there were very rich streaks and spots in the mine then as now, but it seems probable that those reports give an exaggerated idea of the aver-age yield of the entire mine. If some claims proved rich, others were very poor, and before the mines came under one management, it was probably the rich ones that were reported. There were also persistent rumors that some extraordinary rich yields reported in the early days, covered additions by purchase of stones from undisclosed sources. It is generally acknowledged that the volume of illicit trading was very large, and it is equally certain that the most successful traders escaped detection. As such transactions could be concealed in no other way so readily, nor the purchases be disposed of so easily, the presumption is that among so many, some of the claim owners took advantage of the situation. There has been an apparent decrease in the yield per load of most of the mines as they have been carried deeper. The De Beers and Kimberley have steadily declined from over one carat per load in 1888 to .80 of a carat in 1898 and .37 in 1908. The Dutoitspan, which from the beginning gave a small average yield, has nevertheless held very steady, dropping by one hundredth of a carat only in the yearly average from .26 in 1905 to .23 in 1908. When first reopened in 1904 the yield was only .12. The yield of the Wesselton also has been very uniform, being the same in 1908 as it was in 1898, i. e., .27 of a carat per load. In the interim it has never been less than .28, and in 1907 it was .32. The Bultfontein shows an increase from 1902, when the yield was .21 of a carat, to .41 in 1905, since which it dropped again to .32 for 1908. The increase of the first four years after the consolidation began to operate it, is accounted for by the fact that there was an accumulation of poor material which was first cleaned up. The Koffyfontein runs even ; .473 in 1906 and .476 in 1907.
Of the open-cut mines, the Premier of the Transvaal shows the greatest decline in average yield. In the beginning, like the Kimberley, it was very rich, running at times over two carats to the load; it is now about .30 of a carat. The Roberts-Victor also, which opened up with a yield of .91 in May, 1906, dropped to an average of .536 for the year 1907. Part of this apparent deterioration is undoubtedly due to the fact that when a mine is opened, especially if the entire chimney is under one management, the most promising spots are worked first, whereas when the mining is deeper, not only must the entire area be worked, but the left-over part of the higher levels have to be taken down and included. The showing of the Premier and the Roberts-Victor illustrates the probable conditions of the Kimberley when it was first opened, but which did not appear, because there was no exact report of entire results, but uncertain returns from some of the many owners of parts of the chimney. It will be noticed that most of the mines eventually settle down to a yield of from one-quarter to one-half of a carat per load, especially after the open cut is abandoned and underground working begins, when there is not the same opportunity to make selections, but good and bad sections are worked together.
A number of true pipes have been discovered. In the eighties already, some fifteen were known in the Kimberley district and the Orange Free State. Many of them, however, yielded but little, and are comparatively unknown. There are several other mines in addition to the five mines of the De Beers Consolidation, in the Kimberley section. The Peizer, the New Weltevrede and the Frank Smith, north-west of Kimberley. In the Orange River Colony are the Jagersfontein, Lace, Koffyfontein, Monastery, Kaalvallei, New Driekopjes, New Randfontein Reef, Voorspoed and Roberts-Victor. The Elandsdrift Diamond Mining Company and a smaller company, are on a large pipe in the heart of the Vaal River diamond country. Near Pretoria in the Transvaal are the Premier, Schuller, Kaalfontein, Montrose and Beynespoort. Of all these, the most important are the Jagersfontein, Premier, Roberts-Victor and Voorspoed. The output for these four mines for 1907 being:
Carats. Premier 1,889,986 3/4.
A total of nearly thirty-one million carats, to which may be added, in order to make a fair estimate of the entire production of South Africa in the ten years, five per cent. for thefts and the product of the alluvial de-posits and other sources; a grand total of thirty-two and a half million carats. At the same time (1907), the De Beers group alone had in sight above the lower levels of the mines and on the floors, 57,409,013 loads of blue, which at present average yield would represent in round figures over seventeen million carats more. Reckoning the value of the output for the ten years upon a basis of the average price realized by the De Beers group, during that time, South African diamonds must have realized over seventy-eight million pounds sterling.
Even these stupendous figures do not give an adequate idea of the reservoir of diamonds which exists in Africa. How deep these diamond chimneys now being worked, go, is still unknown, and reports are constantly coming in of new pipes discovered, and of large fields of alluvial deposits which indicate the existence of other pipes yet undiscovered. The source of the Vaal river diamonds cannot be from the Kimberley mines, as a ridge intervenes. The drainage also of the Wesselton, Bultfontein, and Dutoitspan is in another direction. The stones also differ in appearance. It would appear, therefore, that the source of the river diamonds has not yet been discovered. The chairman, at a general meeting of the Option Syndicate, held in London lately, said that Mr. Nichols, an engineer sent expressly to Rhodesia to prospect that territory, proved by numerous borings the existence of deposits greater in area than the De Beers and Premier. Diamond-mining is increasing in German Southwest Africa, and the indications are, after making full allowance for the hopefulness of prospectors and the imagination of promoters, that the immense territory of Griqualand, Orange River Colony, the Transvaal, Rhodesia and contiguous land, is honey-combed with diamondiferous chimneys, with many miles of alluvial deposits lying between them.
The following illustrates the changes which have occurred in the method of diamond-mining in South Africa in the last thirty years. Up till 1877, one person could have but two claims in the Kimberley unless he was the discoverer of a mine, in which case he was entitled to hold two in addition to his discovery. In the beginning of 1909 the De Beers Consolidated Mines Company practically own and control the De Beers, Kimberley, Bultfontein, Dutoitspan, Wesselton and Jagersfontein mines entire. In the seventies there were about sixteen hundred individual owners of the Kimberley, the smallest chimney of the Kimberley group. The New Premier of the Transvaal, more than four times as large as the whole Kimberley mine, and equipped now to turn out three to four million carats per annum, was opened up and is owned by a single company capitalized at eighty thousand pounds. A digger in the Kimberley could take up his choice of the free claims, by paying a tax of ten shillings a week; the De Beers Consolidated Mines Company paid in 1908 a tax on the profits of 1907 to the Cape Colony amounting to £302,-174.
Looking backward, one realizes that the change from separate ownerships to the united control or single management of an entire chimney was inevitable. When with increasing depth the reef began to fall in, covering up claims sometimes with millions of cubic feet of worthless material which must be taken out at enormous expense before any further returns could be had from the buried claims, the miners found that some united action was necessary to insure themselves against disasters which threatened all, and would be ruinous to those who chanced to be the unfortunate ones. The Kimberley Mining Board was therefore established in 1874, to remedy all mishaps, and assess the cost upon all the owners pro rata. Thereafter each one was obliged to pay his share of these expenditures for the common interests, or sell his claims. This resulted in the sale of many claims, usually to companies who were in a better financial position to pay these big charges and wait for the profits which would accrue later. And as these companies acquired more claims, if one was covered by fallen reef, they had others from which they could be drawing money to offset the charges made upon them, whereas if a man's single claim were buried, his income with which to pay charges was buried with it.
The consolidation of the mines was therefore a result of the force of circumstances, for which shrewd men on the fields, who foresaw what the trend of things must lead to, prepared themselves financially, both by husbanding their own resources, and also by establishing connections with men of large capital. This was done in a smaller way in the Kimberley by Barney Barnato, simply as a money-making affair, and on a larger scale by Cecil J. Rhodes when he forced an amalgamation of all the Kimberley mines.
Some idea of the extent and power of the De Beers Consolidated Mines Company may be had from the statement of Mr. Gardner J. Williams, the former manager, that it occupies 200,000 acres, employs 15,000 natives and 2,500 white men; (in 1906 the five mines employed nearly 24,000 natives, but owing to the 1907 panic in the United States, the number of employees had been reduced by the end of 1908 to 12,278), consumed monthly in the compounds 250,000 tbs. of mutton, 200,000 its, of beef; uses 6,000 tons of coal a day; has 2,000 horses and mules, and keeps 12 stallions of the best breeds and 200 brood mares, and this in a country that a little over thirty years ago was over four hundred miles from the nearest railroad and port, and was obliged to transport most of the necessities through an undeveloped country by ox or mule wagons. At that time coal cost at the diggings eighty dollars per ton; wood, one dollar and seventy-five cents per one hundred lbs. ; eggs were seventy-five cents a dozen. The first machinery used cost fabulous prices. A hundred horse-power engine cost forty thousand dollars delivered in Kimberley. Transportation from Port Elizabeth or Cape Town ranged from two dollars and fifty cents to seven dollars and fifty cents per hundred pounds. Wages were also very high. White men in the mines got from twenty to forty dollars per week; natives five to eight dollars. In the seventies, as the companies being floated sought to acquire properties, the price of claims soared until some of them brought as high as fifty, seventy-five thousand dollars, and even one hundred and fifty thousand dollars each.
Washing machines were first used in 1874 and not-withstanding the great cost, more machines were introduced from year to year, as they were found to earn many times the cost, in the saving of labor and the increase of yield and production.
After the railroads from Cape Town and Port Elizabeth were brought into Kimberley in 1885, prices fell. English coal could then be had for forty dollars per ton; wood for fifty cents per hundred pounds. Freight rates dropped to about $1.50 to $2.00 per hundred lbs. Wages fell. At present, they range in all the mines, from fifteen to twenty-five dollars per month and lodging for natives, and sixty to one hundred dollars per month for whites in the mines and prospecting.
All the diamond chimneys of South Africa contain the same kind of rock, now called kimberlite, and wherever that rock is found it contains more or less diamonds. The hardness of it varies in different mines, but it usually grows harder with depth. For this reason open-cut workings have an additional advantage in cost over those operated on the underground system. In the underground workings, shafts are sunk in the reef about two or three hundred feet from the chimney, and tunnels cut from them into the kimberlite, which is run out on cars and hoisted to the surface. Taken from these low levels the rock is hard and not fit for the wash-ers. It is therefore spread out on " floors "; large level stretches of ground, and exposed to the weather. The rain and sun disintegrate the rock and make it friable. Six to twelve months are usually given to this operation, though it is sometimes hastened by sprinkling and harrowing. Near the surface, the rock is softer and does not require any exposure. An open-cut mine saves this expense. The New Premier runs its diamondiferous material, which is unusually friable, direct from the mine to the washers, and as it is very much greater in extent than any other, it will have this advantage over the older mines for some time to come. While they are constantly increasing the depth and consequent cost of working, the Premier will simply spread itself over a greater area of workings, in material that will not require the cost of spreading, nor the loss of time in weathering.
Though the kimberlite of all the mines is the same, the diamonds from the various chimneys are so characterized by differences, that men acquainted with the mines can usually tell from which mine a parcel of crystals comes. Some have claimed that there are those who can designate not only the mine but the part of the mine from which any crystal submitted to them, was taken, but this is an exaggeration, for though the stones from the different mines are generally characterized by certain peculiarities, all kinds of stones are taken from all mines. The Kimberley, though rich in diamonds, has been distinguished by generally poor quality. This mine has furnished a much larger percentage of bort than the other mines of that district. Great quantities of fragments of crystals, smoky stones and yellow stones, have been found in it and the different kinds were quite constant in particular sections of the mine. It is notice-able that the part of the mine which lies in the direction of the Dutoitspan, carries a similar class of crystals.
In the De Beers, one finds all kinds and colors, but the surface of the natural facets are finely granulated, and have a somewhat greasy luster similar to the luster of many of the cut Premiers.. As in the Kimberley, fragments are abundant, but there is less bort and the crystals run larger and have more color (yellow) than those of the Kimberley.
The diamonds of the Bultfontein are mostly small, white, flawy octahedrons.
The Dutoitspan diamonds show more color than any, many of them being sufficiently deep and fine to be classed as fancies. Large and also very small stones are found, and the crystallization is usually very good.
The Wesselton crystals are noted for their perfect octahedra and purity. The color and brilliancy are so superior that very fine white diamonds similar to river goods are now quoted as Wesselton. The average yield of the mine does not however command as good a price as that of several others.
The kimberlite of the Jagersfontein mine is free from pyrites, and to that is attributed the remarkable purity of color for which the stones of this mine are celebrated. They are very brilliant and the color inclines to blue. For this reason, " Jagers " command the highest price of any South African diamonds, except blue rivers and some of the fancies of the Dutoitspan. In common with all stones of this character, they are very subject to bad flaws and what are termed carbon spots. The percentage of flawy stones is so great that the average price of rough from this mine is less than that of several others.
A large percentage of the diamonds of the New Premier of the Transvaal is bort. Of those suitable for gem purposes, many are characterized by an oily luster similar to that of the zircon. The color inclines to blue, often of a very deep tint, but it is frequently a false color, that is, tints of other colors show in some lights. An unusual number of very large stones has been found in this mine, some of them of extremely fine color and purity.
The Voorspoed promises to be a large producer of low grade diamonds. The Roberts Victor on the contrary yields a good average of white fine material. The diamonds of one mine, the Leicester, differ from those of any other. The crystals are cross-grained and have a frosted, etched appearance. They are difficult to cut. These marked variations between the diamonds of different mines suggest not only a difference in the forces causing the crystallization, but the presence in some cases of elements in varying degrees and conditions, which were absent in others during the process of crystallization.
Following the methods of India and Brazil, it is customary in Africa to encourage diligence and honesty among the workers in the mines by a system of rewards. If a white miner finds a diamond in the blue while it is yet in the mine, and reports it to the manager, he is credited with three shillings per carat, a native gets six pence per carat. If the stone is found on the floors, the reward is one-half as much. The I. D. B. act, which did not permit a native to have a diamond in his possession, and obliged a suspected white man to prove his right to possess any he might have, if it did not en-courage honesty, did much to discourage dishonesty. Some of the natives, however, are such inveterate thieves, that cases have been known where, with little chance of getting away with them, they have swallowed so many that death resulted. It is reported that sixty carats of diamonds were taken from the body of one who died under suspicion. The compound system inaugurated by the De Beers Consolidated Mines Company is the greatest preventive. The natives are obliged to sign a three months' contract, during which period they must remain in an enclosure on the company's premises. This is a large square of about twenty acres, surrounded by rows of one story buildings of corrugated iron, divided into rooms, each holding about twenty natives. Every provision is made for their health and well being. There are stores which sell the necessaries of life at reduced prices. Wood and water are supplied free of charge. There is also a hospital with medical attention, nurses and food, free. There is a large swimming bath in the enclosure, also a space for games, dances, concerts, or any amusement the natives may desire. Some of them save their wages, giving it to the superintendent to keep for them, quite content if he will show them the money when they ask to see it. Many of them re-new their contracts again and again without leaving the compound; some of the married men do the same, sending money to their wives from time to time. Before leaving the compound they are subjected to a rigorous bodily examination, and held sufficiently long to make swallowing diamonds useless. Men of the various tribes represented keep to themselves. There are some of almost every tribe, Kaffirs, Hottentots, Zulus, Griquas, Fingus, Basutos, Matabilis, Bechuanas, Swazis, Koranas and others.
The prices obtained for Cape rough diamonds up till the time when the De Beers Consolidation was formed, cannot be definitely stated. Prior to that the market was open, assortments were not nearly as close as later, and ideas of value from former conditions yet prevailed. India and Brazil produced few stones of great size, therefore large stones brought a big advance per carat over those of ordinary size. This idea of relative value influenced prices for some years, until the abundance of large stones found in the African mines forced a readjustment of the comparative values of sizes. Though there is no evidence that the method of reckoning the value of diamonds by the square of the weight at a base price ever existed except as a trade fable furnished to writers, large stones did command very large prices from the public, and much more proportionately than now, from the trade. But definite prices for any size or color did not exist until the De Beers Consolidation. Competition, a variable demand, and many men new to the industry, both at the producing and selling ends, conspired to make many irregularities and constant variations in price. Nor was the rough as closely assorted as it has been since the Diamond Syndicate undertook to market the product of the mines. In these days a parcel of rough will cut very close to what it is sold for; in the early days of the Kimberley there was often a wide range of color and perfection in a lot.
The prices are the average for the output of the mines, and cover a wide range of prices for the various qualities. They are also the prices paid to the mines by the Diamond Syndicate, as there was little selling independent of the Syndicate until 1908.
It will be noticed that the Jagersfontein, which produces the finest diamonds of any, yields a money value per load of blue much less than the De Beers and Kimberley, which give a much poorer grade of diamonds, and only about one-seventh of the new Roberts-Victor, which yields a large percentage and good quality both. It is doubtful, however, if this difference will long exist, as the average yield of the Roberts-Victor has fallen fast ; nevertheless, like other new mines, it can be worked at much less cost than the older ones. This mine from May, 1906, when it was opened, to the end of December, showed a profit, after paying all the expense of prospecting, developing, mining operations and registration, of £39,045 from 20,406 carats found.
One of the most important processes in winning diamonds from the matrix is the weathering. The " blue " of nearly all dry diggings is refractory. It is about as hard as sandstone. It was found, however, that exposure to the weather crumbled it so that it could be washed without further preparation. Level pieces of ground hardened by heavy rollers were enclosed convenient to the mines, tracks laid, and the blue as it was taken out of the mine, was loaded on cars and carried to these depositing floors or " Floors " as they are called, where it was spread and left exposed to the weather. According to the nature of the blue, which varies in hardness, it takes from two to twelve months to make it sufficiently friable for the washers. An abundance of rain with hot sunny days intervening, hastens the process, and if rains fail, the miners sometimes water and harrow it. That there may be no interruption to the work of the washers, it is customary to keep sufficient blue on the floors at all times for two seasons' work. If the work of mining were at any time suspended, a mine could nevertheless turn out a full year's supply of diamonds, after the mine was shut down. In 1906 the De Beers mines had 8,300,000 loads on the floors.
When the blue is sufficiently weathered, it is put on trucks and taken to the washing machines, where it is agitated with water, and forced through a series of revolving cylinders perforated with holes one inch in diameter. Lumps which resist the process are returned to the floors or sent to the crushing rollers. The gravel which is left from the washing is worth about £150 per load. A load of the blue as it went in would be worth about 30s. The gravel is then sent to the pulsators : steel sieves with holes from one-sixteenth to five-eighths of an inch in diameter, which separate the sizes. The small sizes are conveyed to a washing pan and the larger ones to revolving picking tables, where the large diamonds are taken out. All the remaining stones then go to the grease-shaking tables. In 1897 an employee of the De Beers named Fred Kirsten noticed that of all the minerals contained in the blue, only diamonds would adhere to grease. This resulted in a machine which not only separates the diamonds mechanically much more rapidly than it could be done by hand, but surely secures all that are present, however small they may be, and prevents opportunity for theft. It consists of a series of sloping corrugated iron tables which are coated with grease and shaken by percussion as the gravel goes over them. Everything but the diamonds passes on, they alone adhere to the grease. The tables are then cleaned, and the process repeated. It is said the grease, after being used awhile, loses its power over the diamonds, but regains it after being melted. The crystals are then cleaned in a mixture of acids, assorted, weighed, registered, and added to the stock in readiness for shipment. As a precaution, the grease tables are arranged in series, though a diamond seldom escapes the first table; about one-third of one per cent. only. It is said none ever yet got past the second.
Perhaps nothing illustrates more strikingly the potency of conditions in the United States, than the effect of the panic here in November, 1907, upon the diamond mines of South Africa. The De Beers closed down a large part of their works in 1908; reduced their expenses £100,000 per month; to avoid the British income tax, turned their London headquarters into an office for the transfer of shares only, transferring their headquarters to Kimberley, and borrowed a million pounds on the security of their investments. It paid the Cape Colony £302,174 as a tax on its profits for 1907, and estimated the tax for 1908, including the British income tax to April 1, at £110,683 only. The Jagersfontein reported sales to March 31, 1908, at 53S. 1d. as against 71s. formerly. Premier goods dropped from 18s. per carat to 14s., and the big Transvaal mine cut down its production some thirty thousand loads monthly. The Diamond Syndicate did not renew its arrangement with the Premier to market the diamonds of that mine, nor did it exercise its option with the Consolidated Mines on December 21, 1907, thereby terminating its contract, and it is claimed on good authority, that contrary to the policy steadily maintained hereto-fore, of holding the market price of diamonds, it made sales during 1908 at a cut on 1907 prices. According to the Frankfurter Zeitung, the De Beers Consolidated made sales to the Syndicate early in the fall of 1908 at a 25 per cent. reduction.
Among the valuable items of information gathered by experience in the mines is one relating to timber. It has been found that California redwood outlasts any other wood used. Redwood sleepers after being ten years in the ground proved to be as sound as when first put in, whereas those of Oregon pine, Puget Sound cedar, African yellow wood, and Baltic deals, were decayed and had to be replaced.
Compared with the yield of the dry diggings, that of the wet diggings are and have been since the first discovery of the chimneys, inconsiderable, nevertheless they are worked to-day as they have been from the first. It does not require much capital to search for diamonds along the rivers, and there is a fascination about its uncertain results which holds many men to the work, and constantly draws recruits. The diamonds are usually of finer quality than those found in the chimneys, and sufficient large ones are found to excite expectation among those who haunt the river diggings. In October, 1907, a man named Harrison found one weighing 31 carats, at Klipdam in the Vaal river fields. Three weeks later he found another which weighed 220/ carats. This he sold for 12,420, and it is reported that it is worth more. A number of large stones have been found in these river diggings, among them, the Star of South Africa, of the finest quality, weighing 83/ carats, at Klipdrift, and the Stewart, which weighed 2883/8 carats, at Waldeck's Plant, both on the Vaal river. Diamonds have been found in wet diggings along the Vaal, Vet, Modder and Orange rivers. On the Vaal the diggings extend over a distance of about 200 miles as the river winds, from the junction of the Vaal with the Orange river, to Bloemhof in the Transvaal. Some of the principal points are Waldeck's Plant, Delport's Hope at the junction of the Vaal and Hart rivers, Good Hope, Barkly West, Pniel, Klipdam, Wedburg, Fourteen Streams, and from Hebron to Bloemhof and Christiana. There are a few companies, but a majority of the miners are independent diggers. The work is done by Kaffirs, and the white men oversee them.
The terraces and river gravels vary in depth from a few inches to 40 or 50 feet. In Smith's Gully at Waldeck's Plant, the diamondiferous material was found, on reopening it after the Boer war, to be 75 feet deep. In some cases these deposits extend laterally three or four miles from the river, and in places there appears to have been more than one period of sedimentation; the pebbles in the last have a matrix of stiff siliceous clay. In the gravels are large greenstone bowlders filled between with sand and pebbles, the whole resting on a floor of amygdaloidal greenstone. The pebbles are principally siliceous; jasper, chalcedony, agate, and with them, greenstone, ironstone, ilmenite, garnet, topaz and diamond. The diamonds are usually dodecahedral crystals, free from flaws. All colors are found, though a yellowish tint predominates. Mr. T. E. Coe says that the deep places are the result of a period of great erosion, as the steep channels were worn through hard diabase and were filled with sand, pebbles, and bowlders much rolled and smooth. In some cases this deposit was overlain with red sand, the " rooi-grand " of the early Dutch digger. The bed rock of these deep places consists of Karoo shale on a bed of amygdaloidal diabase. The diamonds are not distributed uniformly through the deposit, but are found in " bantam" layers; beds of smooth pebbles of moderate size.
The Zaud deposit near the Wedburg placers has an unusually thick layer of the surface sand in which most of the early wet diggings was done. Now, where open working is not practicable, shafts are sunk to the lower layers of gravel, which are richest in diamonds, and it is taken out by tunneling.
From the nature of it, the yield of an alluvial deposit is uncertain and irregular. Mr. T. E. Coe stated that 116 carats of diamonds were taken at the Zaud Kopje in the first two months of 1903, from 1,340 loads of gravel. This would equal only 0.087 of a carat per load, but they sold for 94S. 6d. per carat. The alluvial diamonds of the Transvaal in 1898 amounted to 12,283 carats, and brought £35,228, or a fraction over 57s. 4d. per carat. The diggings at Christiana on the Vaal in the Transvaal in 1907, yielded 2,562 carats and sold for £13,579, or 106s. per carat. The output of the Vaal river diggings for 1905 is given as 8I,749 carats, at an average value of 77s. 7d., and for 1906 as 101,-607% carats at 77s. 3d. The alluvial diggings of the Orange River Colony for 1907 yielded 7,102 carats valued at £36,895, or I03s. 8d. per carat.
It is doubtful if all the wet diggings of Africa have exceeded an average of 100,000 carats per annum since the discovery of the Kimberley pipes. The diamonds, however, have probably brought an average of fifty per cent. more than the average for the dry diggings.
The territory in which diamondiferous deposits and chimneys in Africa are known to exist, is spreading constantly. Alluvial deposits containing diamonds have been found east as far as longitude 28° E. in the Orange River Colony and the Transvaal; west to German South West Africa; north to the watershed of the Limpopo and Zambesi rivers in Matabeleland at about 19° S., and south to about 31 ° S, in the Orange River Colony.
Numerous diamond-bearing pipes have been discovered, and though many of them do not contain sufficient diamonds to pay the cost of working, they indicate that volcanic dykes of that character are not uncommon, and are not confined to a narrow limit. From the Jagersfontein mine near Fauresmith in the Orange River Colony, to fifteen miles north of Kimberley, a range of over 100 miles, there are quite a number of pipes. In the Pretoria district of the Transvaal also, and the Kroonstad district in the Orange River Colony, there are clusters of them, and the character of the crystals found in the deposits along the Orange, Riet, Hart, Vaal and Modder rivers, together with the enormous alluvial deposits lately discovered in Rhodesia, indicate that other great diamondiferous chimneys exist elsewhere, probably at a considerable distance from any known at present. In 1906 Rhodesia exported diamonds valued at £25,469.
Rhodesia, a name given in honor of Cecil J. Rhodes, comprises Matabeleland and Mashonaland, two well-watered districts which will undoubtedly prove ere long to be not only most favorable for colonization by white men, but very productive also agriculturally, and rich in minerals. The territory is governed at present by the Chartered British South African Company, from whom the South African Option Syndicate, formed in 1902, have secured an option granting discoverers' rights to locate 200 square miles to work for precious stones. This section, which the latter company is prospecting, lies along the Buluwayo and Gwelo R. R. In the Somabula forest, about 12 or 14 miles east from Gwelo, the company's prospectors have discovered a diamondiferous area of about 45 square miles, over which there is an alluvial deposit ranging from a few feet to 25 feet in depth. The company controls 65 square miles. They reported in the early part of 1906, that in 30 days they recovered from the rotaries over a surface 56 yards long, some diamonds, 3,320 carats of chrysoberyl, sapphire and ruby, and other precious stones which brought the total up to 7,470 carats, at the rate of 2.14 carats to the load. In the autumn of 1907 they re-ported 4,000 carats of diamonds and 44,000 carats of other gems won up to that time. The deposit is located in an open valley, about 6,000 by 3,000 feet, between ridges in the Somabula forest, and is watered by the Somabula river. At the head of the valley lies the great watershed of the Zambesi and Limpopo rivers. As the district has an elevation of about 4,000 feet, it seems probable that the source of the deposit exists somewhere in the neighborhood, in large diamondiferous chimneys similar to those of Griqualand West, the Orange River Colony, and the Transvaal.
The gravel contains enstatite, olivine, ilmenite, burnt-garnets and mica, garnets, chrysoberyl, sapphires, rubies, amethysts, jasper, iron conglomerite, and diamonds. The presence of some of the softer stones suggests that the source from which the deposit came is not far distant. It is probable that diamonds will be found north also, in Mashonaland, for Keane says in " Africa " (Vol. II, South Africa) : "In 1894 a survey of the Labangwe affluent of the Zambesi gave indications of diamond-bearing ground." The Somabula alluvial is now practically deserted, as diamond pipes have been discovered lately at Bambesi and are being developed.
The largest, named the Colossus, is claimed to be larger than any other known.
A claim of contract between the Chartered Company and the De Beers Consolidated Mines Company made by the latter company, operated until now against a vigorous prosecution of work in the Rhodesian district. It was fought in the courts and decided in the Chancery division of the High Court, February 10, 1910, against the De Beers Company.
That the De Beers Consolidated Mines Company consider the control of these fields a matter of vital importance, is shown by the fact that they have since decided to take the case to the House of Lords, though the Court of First Instance and the Court of Appeal both decided in favor of the Chartered Company, and the feeling of the settlers of Rhodesia is strongly against the Cape Colony Company. This action of the De Beers, however, prevents immediate development, and in the meantime they have unloaded more diamonds on the United States during the last year than in any year previous.
Diamonds have been discovered in considerable quantities lately in German South West Africa near the coast at Lüderitz Bay, formerly Angra Pequena Bay, longitude 16° E, and latitude 26° S. The fields are located near the town of Lüderitzbucht. A syndicate headed by Senator Achelis was formed in Bremen as far hack as December, 1902, to search for diamonds in this colony. The German Colonial Company now holds the mining rights over a territory having 300 miles of coast line and extending 60 miles back. The Calanan's Kop Diamond Company and the Staunch Company, each have a fifty year lease of about 15 square miles on the diamondiferous deposit, and another company, the Weiss de Meillon Company, have one on a tract of three or four square miles. It is reported that the district is producing 12,000 to 15,000 carats monthly. The quality and color of the stones are good, but the crystals are small and cut to a fine grade about 1/2 of a carat.
The diamonds occur in a deposit of sand and gravel said to range from six to twelve feet in depth and traceable in one place, a quarter of a mile wide, for 17 miles. The gravel is sieved as in other wet diggings, and the water for washing is obtained either by pumping from the sea or by digging shallow pits, into which sufficient water for the purpose collects.
In January, 1909, the Emperor William issued a rescript establishing a government monopoly of the trade in all diamonds found in the Colony. All the stones found must be turned over to the representative of the government, who will sell them and after deducting expenses and a tax which, together amount to about one-third of their value, will turn over the remainder of the proceeds to the owner. The present owners of the diamond properties have agreed to form a joint stock company to act as the government's representative.
The output of these fields has already materially affected the price of small diamonds and as they are now under the direct supervision of the German government, they should be beyond the control or influence of the English Diamond Syndicate. An apparent in-ability for any but a favored few to obtain the rough in 1909, followed by a rise of price to the Syndicate level, aroused suspicion of German freedom from syndicate influence. It is rumored, however, that German colonial officials are being investigated. The Transvaal and Orange River Colony should be equally free, as the governments of those colonies are practically partners in the mines within their borders, and therefore probably will not allow a syndicate operated for the benefit of the Cape Colony mines, to restrain their out-put for the purpose of holding up prices to a figure profitable to the Cape mines. The diamond industry is in a critical condition. For twenty years the De Beers Consolidation, having control of the supply and aided by an abnormally good demand, has made prices, holding supply to the demand. That control lost, it appears probable that the ancient millstones of economic principles will once more grind supply and demand to a natural adjustment with the cost of production, though it must be admitted that by shrewd manipulation, prices now (1910) have been restored to the levels existing before the panic.
In 1908 the De Beers group of mines produced 2,177,191 carats. These were not all sold and prices realized were lower, £800,000 only being distributed in dividends as against £2,550,000 in 1907. The De Beers and Dutoitspan mines were closed. The average yield per 100 loads in 1908 was about the same in the De Beers, Kimberley and Bultfontein as in 1907, but a little less in the Wesselton and Dutoitspan.
A new alluvial deposit was discovered July 16, 1908, at Harrisdale, 14 miles from Kimberley. The gravel runs from four inches to three feet thick. £20,000 worth of diamonds of excellent quality were reported in the first six weeks, averaging £8 per carat.
The Transvaal produced in 1908, 2,184,490 carats lued at £1,879,551, principally from the Premier, though 11 other companies and the alluvial diggings at Christiana contributed. The Premier output was for their year ending October 31, 2,078,825 carats at 14s. 9d. per carat.
Orange River Colony product for year ending June 30, 1908, is given as 505,452 carats valued at £1,069,942. Average price per carat fell from 60s. 6 1/2d. to 42s. 1d., owing to the unstable condition of the diamond market. The greater part of the product came from the Jagersfontein, Koffyfontein, Voorspoed and Roberts Victor mines. The balance came from the Lace, Ebenezer and Monastery mines and the alluvial diggings. The value of the latter was 66s. l0 1/2d. per carat. The Roberts Victor Company paid a dividend of 25 per cent. in March, 1909.
Up to December 31, 1908, the diamonds found in German South West Africa are estimated at 40,000 carats worth $269,000. Since then the German Committee for Colonial Development report that 80 new companies have been formed. The output for the cur-rent year 1909, averaged about 45,000 carats per month and the price has risen from $5.33 to $8 per carat. In seven months of 1909, 273,701 carats worth nearly $1,904,000 were obtained, from which nearly half the amount was deducted by the Treasury. In some places there are several layers of the diamond-bearing pebbly deposits, separated by sand. Of late some diamonds weighing up to six carats each have been found.