Friday, January 16, 2009
Diamond Mines - Roberts Victor Mine
For several reasons the Roberts-Victor mine is one of the most important of the new mines of South Africa. Its initial capital is £160,000, divided in one pound shares. With one exception, the diamonds from this mine have brought the highest price per carat of any. In 1906 the average price 0f the Dutoitspan diamonds was 80s. II.52d., whereas the Roberts-Victor brought only 75S., but in the value 0f the yield per load it far exceeded any other. One hundred loads of Roberts-Victor brought over £260, whereas with a higher price per carat, the yield of the Dutoitspan was so much smaller that one hundred loads brought but a little over £100.
The mine is in the Orange River Colony near Boshof, about forty miles from the Kimberley mines. It was acquired by the present company from the original owners in 1906. At that time there were about ninety claims. The company now owns 500 acres.
Work in the mine began in May, 1906. The percentage of carats per load for the first month was .91, but it fell so that the average for the first year was .698. To the end of December the yield was 20,406 carats, which left a profit after deducting the expenses of prospecting, developing, mining operations and registration, of £39,045. Out of this, however, the Orange River Colony is entitled to a share, the maximum being forty per cent. of the profits.
The output for 1907 was 132,809 carats, but the percentage of diamonds per load was still less, being given as .536. It is considered one of the most promising of all the South African mines, as it combines fine quality with abundance. The diamonds are of very good color and many of the crystals are very perfect and beautiful.
The Voorspoed is an Orange River Colony mine capitalized at £400,000 in £1 shares. Work commenced in 1907, and the first six months yielded 46,340 carats at an average of .21 of a carat per load. They realized an average of thirty shillings per carat. Only one mine yields less in money value per load, the Lace. Nevertheless it is confidently expected that it will be a factor in the diamond market, as it will probably produce three to four hundred thousand carats per annum. The crystals are usually small and of mediocre quality. The average yield including 1909 has been a little over .19 carats per load. The year 1909 yielded a total profit of £53,870.
The Koffyfontein continues to turn out in the neighborhood of ten thousand carats monthly. The output for March, 1910, was 9,803 carats, which were sold at an estimated profit of £7,500. At that time there were over one million loads of blue ground on the floors.
The " Frank Smith," and " Otto's Kopje " diamond mines, are situated in Griqualand West, between the Vaal and Hart rivers about forty miles from Kimberley. The former produced about 23,000 carats in 1904 and 1905 but did not pay and has been closed down. The latter from August, 1900, to July, 1902, produced diamonds which realized £21,425 exclusive of one of 336% carats. It did not pay and was closed at that time and a proposition made to reorganize the company.
In 1909 in German South West Africa, 14 producers won 560,977 carats worth £836,000. Eighty-five per cent. was sufficiently good to cut. The average size of the stones was one-fifth of a carat. About eighty per cent. of the output was sold in Antwerp and Brussels, the balance being distributed in Amsterdam, Germany, London, New York and Paris. The net profits after paying expenses and government charges amounted to £34,500.
Several large diamonds have been found in the Barkly district during the winter of 1909–10: a fine blue-white stone of 90 carats and a very good one of 653% carats at Baboon Island, and one of 35 carats on the Barkly West Commonage.
The diamond chimneys are usually somewhat funnel-shaped at the surface, so that many of the surface locations on the edge of them ran out with depth
The mine is in the Orange River Colony near Boshof, about forty miles from the Kimberley mines. It was acquired by the present company from the original owners in 1906. At that time there were about ninety claims. The company now owns 500 acres.
Work in the mine began in May, 1906. The percentage of carats per load for the first month was .91, but it fell so that the average for the first year was .698. To the end of December the yield was 20,406 carats, which left a profit after deducting the expenses of prospecting, developing, mining operations and registration, of £39,045. Out of this, however, the Orange River Colony is entitled to a share, the maximum being forty per cent. of the profits.
The output for 1907 was 132,809 carats, but the percentage of diamonds per load was still less, being given as .536. It is considered one of the most promising of all the South African mines, as it combines fine quality with abundance. The diamonds are of very good color and many of the crystals are very perfect and beautiful.
The Voorspoed is an Orange River Colony mine capitalized at £400,000 in £1 shares. Work commenced in 1907, and the first six months yielded 46,340 carats at an average of .21 of a carat per load. They realized an average of thirty shillings per carat. Only one mine yields less in money value per load, the Lace. Nevertheless it is confidently expected that it will be a factor in the diamond market, as it will probably produce three to four hundred thousand carats per annum. The crystals are usually small and of mediocre quality. The average yield including 1909 has been a little over .19 carats per load. The year 1909 yielded a total profit of £53,870.
The Koffyfontein continues to turn out in the neighborhood of ten thousand carats monthly. The output for March, 1910, was 9,803 carats, which were sold at an estimated profit of £7,500. At that time there were over one million loads of blue ground on the floors.
The " Frank Smith," and " Otto's Kopje " diamond mines, are situated in Griqualand West, between the Vaal and Hart rivers about forty miles from Kimberley. The former produced about 23,000 carats in 1904 and 1905 but did not pay and has been closed down. The latter from August, 1900, to July, 1902, produced diamonds which realized £21,425 exclusive of one of 336% carats. It did not pay and was closed at that time and a proposition made to reorganize the company.
In 1909 in German South West Africa, 14 producers won 560,977 carats worth £836,000. Eighty-five per cent. was sufficiently good to cut. The average size of the stones was one-fifth of a carat. About eighty per cent. of the output was sold in Antwerp and Brussels, the balance being distributed in Amsterdam, Germany, London, New York and Paris. The net profits after paying expenses and government charges amounted to £34,500.
Several large diamonds have been found in the Barkly district during the winter of 1909–10: a fine blue-white stone of 90 carats and a very good one of 653% carats at Baboon Island, and one of 35 carats on the Barkly West Commonage.
The diamond chimneys are usually somewhat funnel-shaped at the surface, so that many of the surface locations on the edge of them ran out with depth
South African Diamond Mines
The Kaapvaal Craton in central South Africa was blessed with some of the richest diamond-bearing kimberlite dykes on planet earth. Kimberley, the present capital of Northern Cape provence in South Africa, started out as a mining/boom town, becoming ground-zero for the historic South African diamond industry.
It all started in 1866 on a farm near Hopetown, a young shepherd named Erasmus Jacobs found a small white pebble along the bank of the Orange River. That white pebble was passed on to a neighboring farmer named Schalk van Niekerk who sent it to Grahamstown to be identified by a Dr W.G. Atherstone. The pebble turned out to be a 21.25 carat diamond, dubbed the "Eureka."
It all started in 1866 on a farm near Hopetown, a young shepherd named Erasmus Jacobs found a small white pebble along the bank of the Orange River. That white pebble was passed on to a neighboring farmer named Schalk van Niekerk who sent it to Grahamstown to be identified by a Dr W.G. Atherstone. The pebble turned out to be a 21.25 carat diamond, dubbed the "Eureka."
Artisanal Mining
Artisanal diamond mining (aka "small-scale mining") involves nothing more that digging and sifting through mud or gravel river-bank alluvial deposits (above, right) with bare hands, shovels, or large conical sieves. Laborers who work in artisanal diamond mining are called "diamond diggers" (below left). Artisanal diamond mining is a form of "subsistence based" non-mechanized mining that is used in poorer countries throughout the world.
Marine Mining
Marine mining technology only became commercially viable in the early 1990s. Marine diamond mining employs both "vertical" and "horizontal" techniques to extract diamonds from offshore placer deposits. Vertical marine mining uses a 6 to 7 meter diameter drill head to cut into the seabed and suck up the diamond bearing material from the sea bed. Horizontal mining employs the use of Seabed Crawlers (remotely controlled, CAT-tracked underwater mining vehicles) move across the sea floor pumping gravel up to an offshore vessel.......
Placer Mining
Placer diamond mining, also known as "sand-bank mining" (top of page, right) is used for extracting diamonds and minerals from alluvial, eluvial, and or colluvial secondary deposits, and is a derivative form of open-cast mining used to extract minerals from the surface of the earth without the use of tunneling. Excavation is accomplished using water pressure (hydraulic mining), mechanized surface excavating equipment, or hand digging (artisanal mining).
Diamond Mining - Extraction Methods
Diamonds and other precious and semi-precious gemstones are extracted from the earth using five basic mining techniques. These diamond extraction methods vary depending on how the minerals are deposited within the earth, the stability of the material that surrounds that desired gem or mineral, and the peripheral damage that will be done to the surrounding environment. The principle methods of diamond extraction are:
Artisanal Mining
Hard Rock Mining
Marine Mining
Open Pit Mining
Placer Mining
Hard-Rock Diamond Mining
The term "hard-rock mining" (top of page, left) refers to various techniques used to extract gems, minerals, and ore bodies that are in situ, and can only be accessed by tunneling underground and creating underground "rooms" or "stopes" that are supported by timber pillars or standing rock.
Artisanal Mining
Hard Rock Mining
Marine Mining
Open Pit Mining
Placer Mining
Hard-Rock Diamond Mining
The term "hard-rock mining" (top of page, left) refers to various techniques used to extract gems, minerals, and ore bodies that are in situ, and can only be accessed by tunneling underground and creating underground "rooms" or "stopes" that are supported by timber pillars or standing rock.
Gold Standard
Gold Standard is a fiscal system in which a predetermined weight of gold is a standard numerical unit of measurement. Due to high durability and malleability, gold came to be used as a standard unit of measurement.Governments that employed such a standard shared a ‘fixed-currency relationship’ with other Governments.Many contradictions prevail regarding the correct phase of adoption of the Gold standard. Historically, Germany adopted this system in 1871 as an aftermath of the Franco-Prussian War. Gradually this was followed by other countries also such as the USA, France, Spain, India, Austria, Russia and many more. This resulted in the international establishment of the gold standard.
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