credit: hdptcarThe diamond pipeline turns diamonds into the gleaming, polished stones we see set in jewellery in the shops and involves the following processes:
Cutting and polishing
ExplorationDiamonds are found in many countries, but over half are found in African countries such as Angola, Botswana, Namibia and South Africa. They start life often within kimberlite pipes underground. The rock is so named after the first pipe was found in Kimberley, South Africa. The pipes are actually volcanic rock formations. Diamonds are formed deep underground where heat and pressure compress carbon into crystalline structures. Sometimes, molten rock comes to the surface and brings diamonds with it. Explorers test the ground for changes in magnetic fields to detect kimberlite as they are often found where there are anomalies.
MiningOnce diamonds have been found, different mining techniques are used to extract them from the earth, depending on where they are. Most diamonds are extracted by open pit mining or underground mining. The ore in which the rough diamonds are found is then processed and sorted.
credit: Irene2005Diamonds can also be mined from ‘alluvial deposits’, or, to you and I, sand, gravel and clay, which has been transported by eroded water and deposited along the banks of a river, shoreline or on the floor of the ocean. Finally, mining by individuals or communities in the most basic way – by hand – is a third method, known as artisanal mining.
SortingAfter processing at the source, diamonds are then sorted and valued based on a number of facets, including their colour, size and quality. The best stones enter the gem market and any that are left are used in industry.
Cutting and polishingDiamonds arrive at diamond cutting centres for further treatment. The main hubs for cutting are India and China as well as South Africa and Belgium. They are then cut and polished into the shapes we have come to know as brilliant cut’, ‘emerald cut’ and so on. After they are polished, the diamonds are once more categorised by their cut, colour, clarity and carat weight (the four c’s). The gems are then sold to wholesalers. Apart from the awful conditions that can be associated with mining in certain countries, leading to a supply of conflict diamonds on the market, it is the cutting and polishing stage which is the most controversial.
Many diamonds, even those which are apparently conflict-free, are cut and polished in poor conditions. What's worse is that often this is carried out by children, for extremely low wages. India is the world’s largest centre for cutting and polishing of diamonds for the global market and in this city alone, there are 500,000 workers. India spends $10 per carat on the polishing and cutting of diamonds compared to China's $17, South Africa's $40 to $60 and $150 in Belgium. In 1997, the International Labour Organization published a report titled Child Labour in the Diamond Industry. It claimed that child labour is rife in the Indian diamond industry: close to 3% overall and 25% in Surat, India.