Carbon, the othei aliotropic non-metal, is found in two forms, graphite and diamond. Graphite crystals will never become fashionable at mineral shows: they simply don’t hack it. They are shiny but very, very soft and greasy, gray-black, and seldom occur in anything but crystal flakes that are just wonderful for mixing with clay and stuffing into wooden cylinders we call pencils but really don’t need much space in a mineral cabinet. The exception is from the Franklin, New Jersey area where an occasional “ball” of crystals less than an inch across may be found in limestone. This excites the Franklin collectors to no end but they are, after all, brainwashed to think rare massives should form the nucleus of a good display collection! Ticonderoga, New York, has long been a source of large amounts of massive material, hence the pencil of the same name.
If it were not for the diamond, carbon would hardly deserve a mention in this post. However, nothing makes the blood of a female run quicker, or the mind become more scheming, than the possibility of a diamond or two in the offing. There is much to be said for the diamond as an item of possession. As long as the monopoly in the world market persists, the value shall always remain high. Even the recent considerable finds being made in Russia will do little to change the price of diamonds, unless it is up! The Russians may not be too slick in the ways of a free economy, but they are past masters at using a closed market to their advantage.
Diamonds have long been known, being mentioned in the Bible (Exodus and Ezekiel), and being highly prized in most of the ruling families of past history. The first great source of diamonds was India, where some of the largest alluvial stones ever found turned up many hundreds of years ago. The great moguls of that area possessed the finest stones in considerable amounts, and battles and conquests have even been fought to gain possession of particularly good stones. A case in point is the Kohinoor, perhaps the most famous diamond in the world. It was not the largest ever found. That honor goes to the Cullinan, found in 1905, which weighed in at 3,106 metric carats, which is about one and one-third pounds.
The Kohinoor now resides in the crowns of the Queen of England, along with Cullinan 2 and Cullinan 3, the second and third largest stones cut from the South African Cullinan. The Kohinor has been kicking around for centuries, being mentioned first in 1526. It had apparently been owned originally by the Rajah of Malwa, whose family lost it in 1304 to the Sultan Ala-ed-din. The occasion of its mention in 1526 was the Kohinoor’s return to the Rajah of Malwa’s family. The “Mountain of Light” then remained with the great moguls of India until the invasion, in 1739, of India by Nadir Shah of Persia. The Persian Shah knew of the great diamond, which weighed about 186 carats, but after sacking Delhi and capturing the current owner Mohammed Shah, he was unable to find the diamond. Legend had it that the king of Delhi had the stone hidden in the folds of his turban. One of his concubines finally ratted on him, and the Persian Shah developed an elaborate scheme to get the turban without being forced to decapitate his political prisoner. Oddly, prisoners were supposed to be treated with considerable respect. So, Nadir Shah held a large and sumptuous banquet at which is prisoner was hosted. As a gesture of friendship and lasting peace between them, the Persian Shah allowed as how they should make use of an age old custom of exchanging turbans. To refuse was to grossly insult the Shah host. So, Mohammed Shah meekly handed over the turban containing the fabulous Kohinoor!
The 199.6 carat Orloff diamond, currently residing in the Diamond Treasury of the Union of Soviet Socialist Republics, has an even more turbulent past. It started out as the eye of an idol on an island called Srirangen in the Cauvery River in Southern India. Stolen by a soldier and sold to a ship’s captain for $10,000, it ended up in Amsterdam and was finally purchased by Prince Orloff, lover of Catherine the Great. He was attempting to expiate himself after having fallen from favor. It didn’t work, though Catherine allowed as how the diamond was worth keeping nonetheless. The diamond was supposed to have been hidden in the coffin of a priest in the Kremlin. Legend suggests that Napoleon went to the tomb to extract the diamond but when the tomb was opened the ghost of the dead priest arose and scared him away. But for that ethereal protector the fabulous PA x 1 x 3/8-inch stone would be in France’s Louvre today!
The diamond has long been known as the hardest substance found in earth while its isomorphic companion, graphite, is one of the softest. The internal lattice structure of the molecules accounts for this. The graphite is formed of hexagonal plates which are flat and tend to slide easily, while the diamond tetrahedrons hang tenaciously together. The hardness of diamonds was so well-known in early times that they were tested by being struck with a hammer. If the crystal shattered then it certainly couldn’t be a diamond. Unfortunately, the early gemologists hadn’t learned about cleavage, and many a diamond fell victim to this cruel test.
Though the earliest source of diamonds was India it is now almost totally barren after centuries of mining. South America has long been a source of diamonds, though never important when compared to India and the South Africa deposits. These great and most important mines all stem from the lucky find of two children who picked up a “pebble” along the Orange River, in 1867. The story of South Africa’s diamond mines is too long to dwell on here, but suffice to say those mines provide the bulk of the world’s needs today. Russia has some important new fields, but remains only a minor source when compared to the Congo, Sierra Leone, South Africa, and elsewhere on the Dark Continent.
So important have diamonds become that they have now been synthesized under pressures greater than 1’/s million pounds to the square inch, and at temperatures in excess of 2,700°C. Many scientists believe conditions such as these only exist deep in the mantle of the early, a likely source of the volcanic “pipes” which yield the diamonds found today.
Diamonds have been found scattered around the United States, particularly in California, and in the Mid-west where they were brought from some undiscovered source to the north when the glaciers slid over the continent. Murfreesboro, Arkansas is the only place where diamonds are found “in situ” in the U.S. Fine stones, generally of very small size, have been found. Perhaps the largest is the 75 carat “Star of Arkansas.” Operators have unsuccessfully tried to operate the diamond bearing “pipe” in Arkansas, but have been unable to sustain production. Probably the best effort was when the property was opened to lapidarists for a fee. Diligent searching of the loose “yellow ground” sometimes rewarded the seeker with a fine gemstone.