Diamonds are forever

Diamonds are a desirable, highly economic, and extreme form of carbon. The can only formed under intense heat and pressure deep within the Earth; the upper mantle. But if so how do they get brought up to the surface for us to mine them? The answer is kimberlite pipes, the hottest and deepest known rock found on Earth, which periodically erupted through the crust when the Earth was younger and much hotter than it is today. An excellent animation of how this occurs can be found on the 'How stuff works' website.

By looking for kimberlite rocks (which have a slightly blue hue) veins containing diamonds can be found. One such place abundant in diamonds is Akwatia: Ghana’s biggest mining town. It used to contain predominantly large-scale mines, but an exponential trend to small and artisanal mines has prevailed in recent years, as total mining has decreased. This is because these small mines generally set up on the sites that larger companies have already mined, meaning their only option is to scavenge lower carat diamonds.

Graph illustrating the huge increase in small and medium sized mines, compared to large GCD (Ghana Consolidated Diamonds Ltd) owned mines (Yelpaala and Ali, 2005)

Yelpaala and Ali (2005) produced a paper looking at the effects of mining in Akwatia. Compared to the predominantly mined commodity in Ghana, gold, diamonds pose relatively little harm, as the chemical processing involved cyanide and mercury is not required. However, as artisanal and illegal mines grow in the numbers other sources of risk to human health and the environment will rise (a UN study in 2000 estimated that 50,000-80,000 people were engaged in illegal mining in Ghana).

In the process of mining for diamonds, pits must be excavated and then the removed material sifted through for the crystals. GCD (one of the major mining companies in Akwaitia) does this at just 30 to 60% efficiency (GCD, 2002), creating a huge amount of waste and unnecessary environmental disruption.

Men digging a small-scale mine pit

In digging the pits and then refilling them with the waste a great deal of land degradation occurs. Although GCD re-vegetate some of their sites, their small budget doesn’t allow for much. This leads to a loss of plant biodiversity, many of which are medicinal plants relied upon by the local people, particularly in the illegal mining sites where no attempt at protecting the environment is imposed.

When pits are left unfilled they pose human risks; both from a safety aspect of locals falling into them and injuring themselves, and because they fill with water and subsequently become mosquito breeding grounds. For a country with a serious malaria problem that is a dangerous consequence. However, GCD and other companies simply do not have the money to be able to fill all the pits.

To move forward, as is the case in all developing countries, a balance between economic growth and environmental and human impacts clearly needs to be achieved. Sadly there does not seem to be an easy answer as to how this can be done.