They say they are forever and, other than the sentiment supposedly attached from the bearer, they are right in an elemental sense. Diamonds are the hardest substance known to man. On the Moh hardness scale (mineral quality scale used for identification and differentiation of minerals) it rates a perfect 10. The atoms of diamond are arranged tighter than in any other substance, giving the gem its hardness. A diamond can only be abraded by another diamond of higher hardness and diamonds are used to polish other diamonds.
The melting point of diamond is 3,820 degrees Kelvin, making it the highest melting point of any substance. Diamonds are tetrahedrally bonded pure Carbon atoms; they are terrific heat conductors and have a high dispersion of light making them ideal for industrial applications as well as jewelry. This fire and hardness are considered the ideal reasons why diamonds are so typically interpreted as wedding or engagement rings due to their durability for everyday wear.
Diamonds are not particularly rare, although advertising campaigns and big diamond companies would have the public believing otherwise. There is a great deal of controversy surrounding the mining, sale and market value of natural diamonds. Approximately 50% of the worlds diamonds come from central and southern Africa with much of the sales of the gem being handled by paramilitary groups and are sometimes dubbed conflict diamonds or blood diamonds because of the tragic deaths which occur through the mining, sales and transport of these diamonds. Other areas in the world where diamond mines are prevalent are Canada, India, Russia, Australia and Brazil.
Diamonds have been brought to the surface of the earth from deep within the earth where extreme pressure systems and extremely high temperatures caused their original formation. Volcanic eruptions from 1,100 million -20 million years ago carried the diamonds through Kimberlite pipes to the surface of the earth. These pipelines were formed as magma flowed through intense ruptures in the earth. When these explosions occurred, the magma thrust the diamonds through the pipes, bringing them and other minerals rapidly through the mantle and crust without disturbing their structure by pressure or heat. There are some diamonds found on the earth today that are dated as old as one billion years.
Natural, uncut diamond crystals are formed in isometric cubes and octahedrons (8-sided prisms). Diamonds are rated as having high value by color, high refraction, fire (high dispersion), rarity and extremely low reactivity to chemicals. Diamonds can come in many colors including, yellow, brown, blue, green, black, pink, orange, red, purple and violet. The closer the diamond comes to perfect translucence and no additional hues, the higher in value it becomes.
A diamond of a pink or blue hue is also rated as quite valuable due to the rarity of these gemstones and the more intense the color, the higher the diamond is valued. The Hope Diamond, one of the largest diamonds in the world at 45.52 carats, is now housed in the Smithsonian Natural History Museum with an estimated value of $250 million dollars. Diamonds are judged by carat, clarity, color and cut- the four Cs of Diamonds—and are valued and rated by these characteristics.