How the Global Diamond Trade Works
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Dec 18, 2011

How the Global Diamond Trade Works

Have you ever wondered where on earth the diamond in your ring comes from? It could be from any number of places, be ethically sourced or not, and its chain of production been long or short. In this article, we explore the question: just how does a rock turn into a ring?

credit: hdptcar
The 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
Jewellery manufacturing


Diamonds 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.


Once 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: Irene2005
Diamonds 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.


After 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 polishing

Diamonds 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.

Manufacturing and retailing

The diamonds are then bought up by jewellery manufacturers or wholesalers and these are then sold on as required and designed into the pieces that are sold in the shops.


Because of the problems surrounding the Kimberley Process and tracing stones on the market, it is almost impossible for a jeweller to tell a customer whether or not the diamond was cut under unethical conditions. The only way is to find a jeweller who can guarantee sources of stones, such as those that come from Canada. At the moment, Canada is the only country in the world to operate a system to monitor and track diamonds from the mine.

This article was written by - online merchants of ethical jewellery, including art deco, ruby, peridot, sapphire engagement rings and a wide range of other unique jewellery designs.