The nature of Diamonds and Diamond Mining

What is a diamond made of?

Diamonds are transparent gems consisting of carbon.  They were formed near the beginning of time, when earth experienced colossal extremes of pressure and temperature.  Deposits of carbon then began to crystallize deep underground.  As the earth’s surface cooled, volcanic activity brought the magna to the surface – shooting the diamond crystals up with it.  This is how the diamonds came to be encased in vertical volcanic “pipes”.

While the traditional colour associated with diamonds is white (or no colour at all), they do, inf act, come in many different shades.  Colours include: white, yellow, blue, green, champagne, pink (the rarest and most valuable diamond in the world), pink champagne (a pink diamond that displays flashes of pink, the secondary colour) and white champagne (a white diamond that displays flashes of pink, the secondary colour). 

Thanks to their atomic structure, diamonds are considered to be the world’s hardest substance – natural or synthetic – beating rubies, the second hardest substance, thousands of times over.  Diamonds retain their elegant cut, corners and sharp edges after many years of wear and tear, whereas most other stones will become chipped or scratched. 

But this doesn’t mean diamonds are unbreakable – if given a blow hard enough, in the right direction, they can split or even shatter.

Mining the diamonds

Large areas must be covered in mining for diamonds - approximately 250 tonnes of ore must be mined to produce a one-carat polished diamond.  

Mining for diamonds is done by one of two ways:

• Pipe mining: this method involves extracting diamonds from the volcanic pipes, which consist of “kimberlite”.  The kimberlite is dug from the surface by way of rough, opencast mining, and once surface deposits are depleted, tunnels are dug into the deeper parts of the pipes.  Diamonds are then separated from the “host rock” at a screening plant.
• Alluvial mining: this method involves mining for diamonds along riverbeds and ocean beds.  This is because when the volcanic pipes were formed millions of years ago, some diamonds were actually carried out to sea and deep into the rivers.  In order to reach them, a wall must be constructed to hold back surf, before bulldozing over 20 metres of sand to reach the earth.  This diamond-bearing earth is then taken to the screening plant.

Who mines the diamonds?

More than 20 countries around the world mine for diamonds, the majority of which are found in Australia, Zair, South Africa, Botswana and Russia.  In fact, the world’s biggest diamond-producing mine, the Argyle Diamond Mine, is located in Western Australia in the Kimberley region.  It even produces 95% of the world’s supply of intensely-coloured pink diamonds – the others found in India, Brazil and Africa literally pale in comparison to the Argyle pinks.  Companies such as BHP Billiton and Rio Tinto (which owns the Argyle Mine) are major players in the world diamond mining market.