In this blue clay or Kimberlite in these chimneys, is found nature’s most wonderful creation, the diamond crystallized from pure carbon, in intense heat, and under titanic pressure.
The greatest mines of Africa are the Jagersfontein, Wesselton, Premier and Robert Victor. The Kimberlite of the Jagersfontein mine is free from pyrites, and to that is attributed the remarkable brilliancy and purity of color for which the diamonds of this mine are celebrated. Their color includes the blue, and they command the highest prices of any diamonds.
The Wesselton mine crystals are noted for their octahedra and purity. The color and brilliancy are so superior that nearly all fine white “Rivers” are rated as Wesseltons. The Robert Victor yields a big average of fine white stones, and many of the crystals are very perfect and beautiful. The Dutoitspan diamonds mostly show color, but many are “fancy” and demand a high price. The Bulfontein crystals are usually small white octahedras of very good color, but many are flawed. The De Beers stones are good white, some color, some broken crystals and smoky stones. The Kimberly diamonds are much the same as those from the De Beers mine. The Premier is the largest diamond mine in the world. Of its diamonds some have an oily lustre and are quite blue—many are of the finest quality and color. This mine also produces a large number of “false color” stones which change color in different lights. The Voorspoed and the Koffyfontein produce fair white and some colored diamonds.
Diamonds in small quantities are also found in Borneo, British and Dutch Guiana, Australia, Sumatra, China and the United States.
One of the largest diamonds known (weight 367 carats) was found in Borneo about a century ago, and belongs to the Rajah of Mattan. One of the most celebrated is the Koh-i-noor (Mountain of Light), belonging to the British crown. It weighed originally nearly 800 carats, but by subsequent recuttings has been reduced to 1033⁄4 carats. The Orloff diamond, belonging to the Emperor of Russia, weighs 195 carats; the Pitt diamond, among the French crown jewels, 1361⁄2. The former, which came from India, has been thought to have originally formed part of the Koh-i-noor stone. The largest Brazilian diamond weighed 2541⁄2 carats and was cut to a brilliant of 125. Some of the South African diamonds are also very large, one being found in 1893 weighing 971 carats, or nearly half a pound. More recently a much larger one has been found, weighing 3,034 carats. This has been cut into eleven pieces, the largest, a drop brilliant, weighing 5161⁄2 carats. This, called the Star of South Africa, has been placed in King George’s scepter, and another, of 3093⁄16 carats, in his crown.
A rough diamond is a hard-looking, luminous object, somewhat like a piece of alum, with a dull skin, called the “nyf,” over a brilliant body. The ancients wore their diamonds uncut because they could not find a substance that would grind or cut them. About 1,500 years ago, however, it was found that by rubbing or grinding one diamond against another the outer skin could be removed. At Bruges, in 1450, diamonds were first polished with diamond dust. In Holland, in 1700, diamonds were first cut with an idea of bringing out real beauty and brilliance by cutting them square with a large flat table and some small facets, ten in all, sloping to the edge of the square. From this beginning cutters gradually added additional facets to increase the brilliancy until there were thirty-four in all. Then came the English round-cut brilliants with fifty-eight facets, but the diamond was left thick and lumpy, until about seventy-five years ago, when an American cutter, Henry D. Morse, of Boston, developed the cutting of diamonds to its present perfection by fearlessly sacrificing weight to get proportion. This greatly increased the price of diamonds, but enhanced their brilliancy.
Old Square Cut Diamonds
English Square Cut Diamonds