Diamond History
Stemming from the Greek word adamas meaning "unconquerable," the diamond is the hardest natural substance known to man. On a molecular level, the diamond is the result of one of carbon's two crystallite structures, the other form being graphite. Graphite, commonly used for pencil lead, is relatively weak while the diamond earns a 10 on the Mohs scale of mineral hardness. Its unsurpassed hardness makes it ideal for use as a gemstone since it resists scratching. The only mineral that can scratch a diamond is another diamond.
Diamonds are formed 90-120 miles beneath the Earth's surface as carbon atoms are tetrahedrally bonded together under high temperature and pressure. When a volcano erupts, the diamonds are carried to the surface via kimberlite pipes. Diamonds are found only in two rock types: kimberlite and lamproite. Roughly 3,000 of these pipes are found in South Africa, with some 200 or so occurring in North America and other parts of the world but Europe and Antarctica. From these pipes, approximately 1,000 contain diamonds and a very small percentage (5% or so) can be mined economically. Though this may seem like an insignificant amount, as much as 130 million carats (an estimated 9 billion dollars' worth) are mined annually.
Although diamonds are widely known for their crystal clear color, they appear in various colors ranging from white to black and everything in between. Impurities in the diamonds, like the presence of nitrogen, can change the color of a diamond. For example, nitrogen tends to transform a diamond's transparency to a yellow or brown tinge. Other naturally occurring additives can also transform a diamond's color to pink or blue, red or orange, and a host of other colors. As they are rarely found in nature, these fancy colored diamonds tend to be higher in value.
First discovered and mined in India, diamonds were used either as talismans or as religious icons. Greeks believed diamonds to be tears of the gods and the Romans thought they were splinters of fallen stars. The Romans were closer to the truth as it is believed that meteor impacts are a source of diamonds as well. Scientists have found "diamond dust" at some sites. India ceased to be the world's foremost producer of diamonds when a cache was found in Brazil in 1730. But it was in 1867 when a major source of diamonds was found in Kimberly, South Africa that people rushed to Africa in hopes of discovering additional diamond reserves. Africa continues to be the world's largest producer of diamonds, but suffer some controversy due to conflict diamonds. Revolutionary groups in central and west African countries take over diamond mines and use the proceeds to fund their activities. However, regulation by the Kimberley Process has slowed the introduction of conflict diamonds into the market. This society, consisting of 43 participants worldwide, requires its members to certify that none of their diamond shipments contain conflict diamonds.
Of the diamonds mined, the majority is used for industrial purposes, while the remaining diamonds (20%-25%) are used as gemstones. Due to the hardness of diamonds, it makes them ideal for drilling, carving and cutting hard materials. They are also used as abrasives and may eventually be used as semiconductors due to the strong covalent bonding within the stone.
As jewelry, the practice of giving a diamond engagement ring as a sign of betrothal first began in 1477 when Archduke Maximillian of Austria gave one to Mary of Burgundy. Now the diamond engagement ring has become the customary token of commitment that a man gives a woman.