Introduction of Diamond Formation

A diamond is a transparent gem made of carbon, one of the earth's most common elements. The formation of diamonds began very early in the Earth's history, when the centre of the planet was subjected to incredible extremes of temperatures and pressure.

Diamonds are decidedly one of the most highly valued and fascinating precious gems and considered by all people across the globe as nature's unique gift to mankind. It is interesting to know diamonds evolved - millions of years ago in pockets of carbon dioxide that existed deep beneath the Earth's crust.  Tremendous heat and pressure combined to cause the carbon atoms to crystallize forming diamonds and the intermittent volcanic eruptions brought the diamonds up to the surface.

Diamonds originate from two types of deposits - Primary deposits that consist of diamond-bearing pipes of a volcanic rock called Kimberlite.  From deep inside the earth, these deposits were carried to the surface as molten rock called as magma. The secondary deposits, also referred to as alluvial, were formed as a result of erosion of material from primary deposits. They are said to contain diamonds that have traveled away from their original source.

Diamonds, regardless which type of deposits it emanates from, require special mining techniques. Primary deposits, in which diamonds are contained in Kimberlite pipes, require open pit or underground mining operations. Secondary deposits diamonds require alluvial mining, which uncovers diamonds in riverbed, coastal and marine/undersea locations. Diamonds are created when carbon is put under immense pressure and temperature deep within the earth—at distances of 250 miles or even greater.

It is common knowledge that regardless of the way diamonds are mined, to construct maintain and operate a mine enormous investment and technical skills are necessary. When it comes to open pit and underground mines, crushing is done to uncover the diamonds. The excavation of sand is necessary to find diamonds in coastal mining. Undersea mining entails drilling into the seabed to recover diamond-bearing gravels. Riverbed mining involves some basic equipment such as sieves and pans.

The formation of natural diamond takes place under extraordinary conditions like exposure of carbon-bearing materials to enormous high pressure combined with temperature between approximately 1650–2370 °F (900–1300 °C). It is interesting to know that these mosy unlikely conditions are met only in two places on Earth - in the lithospheric mantle and at the site of possible meteorite strike.

The conditions for diamond formation in the lithospheric mantle occur at considerable depth keeping with the temperature and pressure as detailed earlier. Very small-sized diamonds, known as microdiamonds or nanodiamonds, have been found in meteorite impact craters where shock zones of high pressure and temperature suitable for diamond formation occur. Studies of carbon isotope ratios shows the carbon found in diamonds comes from both inorganic and organic sources.

Even though world diamond production has tripled since 1980, diamonds continue to be a scarce resource. Geologists are using extensive methods in diamond exploration, including satellite surveys, reconnaissance sampling and drilling in the ground. Today, 75-80% of the world's natural diamonds are used for industrial purposes and only 20 to 25% for gemstones. It is the chemical and physical properties of this mineral that give it the superior cutting ability for industrial use.

Some of today’s diamond-producing countries include Botswana, Canada, Namibia, Russia, South Africa, Australia, and Tanzania.