At present the diamond production of India is insignificant. It is notable, however, that in 1881 a fine diamond, weighing 67⅜ carats, was found near Wajra Karur, in the Bellary district, Madras. The stone was cut into a brilliant weighing 24⅝ carats, and is known as the 'Gor-do-Norr.'
Brazil was not regarded as a diamond-yielding country until 1727, when the true nature of certain crystals found in the gold washings of the province of Minas Geraes was first detected. Diamonds occur not only in this province, but in Bahia, Goyaz, Matto Grosso, and Paraná. The geological conditions under which the mineral occurs have of late years been carefully studied by Professors Derby, Gorceix, and Chatrian. The diamonds are found in the sands and gravels of river-beds, associated with alluvial gold, specular iron ore, rutile, anatase, topaz, and tourmaline. In 1853 an extraordinary diamond was found by a negress in the river Bogagem, in Minas Geraes. It weighed 254½ carats, and was cut into a brilliant of perfect water, weighing 125 carats. This brilliant, known as the 'Star of the South,' was sold to the Gaikwar of Baroda for £80,000.
Both the Indian and the Brazilian diamond-fields have of late years been eclipsed by the remarkable discoveries of South Africa. Although it was known in the last century that diamonds occurred in certain parts of South Africa, the fact was forgotten, and when in 1867 they were found near Hopetown, the discovery came upon the world as a surprise. A traveller named O'Reilly had rested himself at a farm in the Hopetown district, when his host, a man named Niekerk, brought him some nice-looking stones which he had got from the river. O'Reilly, when examining the pebbles, saw a diamond, which afterwards realised £500. Niekerk afterwards bought a diamond from a native for £400 which realised £10,000. The principal mines are situated in Griqualand West, but diamonds are also worked in the Orange River Free State, as at Jagersfontein. The stones were first procured from the 'river diggings' in the Vaal and Orange rivers. These sources have occasionally yielded large stones; one found in 1872 at Waldeck's Plant on the Vaal weighed 288⅜ carats, and yielded a fine pale yellow brilliant, known as the 'Stewart.'
Kimberley Diamond-mine.
It was soon found that the diamonds of South Africa were not confined to the river gravels, and 'dry diggings' came to be established in the so-called 'pans.' The principal mines are those of Kimberley, De Beer's, Du Toit's Pan, and Bultfontein. The land here, previously worth only a few pence per acre, soon rose to a fabulous price. At these localities the diamonds occur in a serpentinous breccia, filling pipes or 'chimneys,' generally regarded as volcanic ducts, which rise from unknown depths and burst through the surrounding shales. The 'blue ground,' or volcanic breccia containing fragments of various rocks cemented by a serpentinous paste, becomes altered by meteoric agents as it approaches the surface, and is converted into 'yellow earth.' At Kimberley the neighbouring schists, or 'reefs,' are associated with sheets of a basaltic rock, which are pierced by the pipes. About 2000 white men are employed in the industry, and about 4000 blacks, who earn, on an average, about £3 a week. In the year 1887 the production of the principal mines was over £4,000,000. The production for 1894 was somewhat less, while the total value of diamonds exported from 1867 to 1894 was about £70,000,000.
The great number of large stones found in the mines of South Africa, as compared with those of India and Brazil, is a striking peculiarity. In the earliest days of African mining a diamond of about 83 carats was obtained from a Boer. This stone, when cut, yielded a splendid colourless brilliant of 46½ carats, known as the 'Star of South Africa,' or as the 'Dudley,' since it afterwards became the property of the Countess of Dudley, at a cost of £25,000. Some of the African stones are 'off coloured'—that is, of pale yellow or brown tints; but a large gem of singular purity was found at Kimberley in 1880. This is the famous 'blue-white' diamond of 150 carats, known from the name of its possessor as the 'Porter Rhodes.' At the De Beer's Mine was found, in 1889, the famous stone which was shown at the Paris Exposition. It weighed 428½ carats in the rough, and 228½ carats when cut. It measured one inch and seven-eighths in greatest length, and was about an inch and a half square.
Even larger than this remarkable stone is a diamond found in the Jagersfontein Mine in 1893, and named the 'Jagersfontein Excelsior.' This is now the largest and most valuable diamond in the world. It is of blue-white colour, very fine quality, and measures three inches at the thickest part. The gross weight of this unique stone was no less than 969½ carats (or about 6½ oz.), and the following are its recorded dimensions: Length, 2½ inches; greatest width, 2 inches; smallest width, 1½ inches; extreme girth in width, 5⅜ inches; extreme girth in length, 6¾ inches. It is impossible to say what is the value of so phenomenal a gem. We do not know that an estimate has been even attempted; but it may easily be half a million if the cutting is successful. The diamond has, however, a black flaw in the centre. It is the property of a syndicate of London diamond merchants. The native who found it evaded the overseer, and ran to headquarters to secure the reward, which took the form of £100 in gold and a horse and cart.
Previous to this discovery, the most famous of the African diamonds was, perhaps, the 'Pam' or 'Jagersfontein' stone, not so much from its size, as because the Queen had ordered it to be sent to Osborne for her inspection with a view to purchase, when the untimely death of the Duke of Clarence put an end to the negotiations. The 'Pam' is only of 55 carats now; but it weighed 112 carats before being cut, and is a stone of remarkable purity and beauty. Its present value is computed at about twenty-five thousand pounds sterling.
The most valuable diamond in the world is (if it is a diamond) the famous 'Braganza' gem belonging to Portugal. It weighed in the rough state 1680 carats, and was valued at upwards of 5½ millions sterling.