History
The ancient Greeks supposed diamonds to be minute fragments of stars fallen to earth. Some even believed they were the tears of the gods. The Greeks first spoke of diamonds as adamas – the steel-hard and invincible one. From this we derive adamant, demand and finally diamond. Another legend speaks of an inaccessible valley in Central Asia, whose ground was strewn with diamonds. Birds of prey kept watch over the valley from the air and snakes with death-inducing looks protected the entrance.
Ever since its discovery over six hundred years before Christ, diamond has been the most beloved, cherished and coveted gemstone on earth. For centuries it has symbolised brilliancy, dignity, wealth and beauty. Kings and queens adorned themselves with these sparkling gems, making an unambiguous statement about their power and status. The fates and fortunes of rulers, peoples, families and distinguished personalities have been linked to diamonds.
In the last century, however, scientists and geologists have discovered the secret of their creation.
Colour
Colourless Diamonds: a pure and perfectly structured diamond appears completely colourless. Chemical impurities and/or structural characteristics have an impact on the diamond’s colour, producing subtle nuances of yellow or brown. To the naked eye, most diamonds appear colourless. An expert, however, can distinguish these faint shades of colour which determine the value of a stone. ’D’ is used to describe the most colourless of diamonds. Moving down the scale in alphabetical order from D, each letter describes an increasing intensity of colour in the stone.
Fancy-Coloured Diamonds: a stone with an intense colour is known as a fancy-coloured diamond. These stones are particularly rare and highly prized. Among other things, finely distributed chemical elements such as nitrogen, boron and hydrogen replace some carbon atoms in these diamonds to create wonderful hues such as blue, pink, yellow, green and brown.
Gemmological Properties
Adding to diamond’s magical beauty is its mysterious formation, which links us to the depths of Mother Earth. Diamonds were created between a few million to over three billion years ago within the earth’s mantle, at depths of over 150 km beneath the earth’s crust – a layer not accessible to man.
Diamonds were released from this layer through explosive eruptions from the earth’s interior and embedded in kimberlite rock, which formed as the lava masses cooled. Again, over millions of years, the kimberlite rock was gradually worn away by erosion and the diamonds carried down to riverbeds or the sea coast where they remained for man to discover.
Diamond is the hardest of all natural materials, and its structure is very simple. It is the only precious stone to consist of one single element, namely carbon. If the required pressure and temperature conditions are present, carbon atoms are tightly and strongly bound together by their electronic forces, yielding an exceptionally compact structure: cubic close packing. Thus is a diamond formed. This phenomenon also allows for the unmatched refraction of light, which turns the diamond into a sparkling and eye-catching jewel.
Diamonds are classified into two fundamental groups depending on the presence or absence of nitrogen blended into their crystal structure. Type I diamonds contain minor concentrations of nitrogen, whereas type II diamonds are chemically purer and do not reveal any characteristics related to nitrogen.
Mining Areas
The first diamonds were washed out of river gravels in India, mainly along the eastern side of the Deccan Plateau in India: Golconda remained the only source of diamonds for thousands of years, producing extraordinary gemstones such as the legendary Hope, a blue 44.5 carat diamond, the 105.6-carat Koh-i-noor (Mountain of Light) and the Orloff, weighing 189.6 carats. These deposits, however, eventually became exhausted.
In the late 1720s, diamonds were discovered in Brazil. The gemstone market resisted at first, characterising them as less valuable due to their origin. Eventually these diamonds were smuggled into India and, through trading centres there, introduced into the European markets. The Star of the South, with an uncut weight of over 260 carats, and the President Vargas, weighing over 700 carats before cutting, are just two of the remarkable gems unearthed in Brazil.
In 1866 the first African diamond, a 21-carat rough, was discovered by a farmer’s boy, Erasmus Stephanus Jacobs. This diamond, cut to 10.73 carats and christened Eureka, was exhibited in Paris a year later and awoke enormous interest in the western world. A second major discovery, the 83.50-carat rough Star of Africa, was the spark that set off the explosion: the first African diamond rush. Over the following years, unique treasures such as the Cullinan, 3106 carats, and the Oppenheimer, 253 carats, were discovered.
Historically, South Africa is the most important diamond producer; its most fruitful sources being the De Beers, the Kimberley, the Wesselton, the Dutoitspan and the Bultfontein mines. The Jagersfontein, known as the Queen of South African mines, is the deepest hand-excavated mine in the world, while the Premier mine, renamed as the Cullinan Diamond Mine in 2003, is the largest diamond mine in South Africa.
Today, the biggest diamond producers are Botswana, Russia and Canada.
