Friday, 20 July 2012

The Diamond Supply Chain

Have you ever wondered about where the diamond in your ring came from or the journey that it went on to get there?


Diamonds are found in many countries, including a number of African countries such as Angola, Botswana, Namibia, Sierra Leone, Zimbabwe and South Africa, as well as Russia, Canada and Australia. However, most diamonds started life billions of year ago, within underground volcanic rock formations known as kimberlite pipes. The rock is so named after the first pipe was found in Kimberley, South Africa. 
Diamonds formed under very high heat and pressure which compressed carbon into crystalline structures. When kimberlite pipes comes to the surface they can brings diamonds with them. Explorers test the ground for anomalies in magnetic fields which may indicate the presence of kimberlite.


A range of mining techniques are used to extract diamonds from the earth, depending on where they are. Most diamonds are extracted by open pit mining or underground mining. 

Diamonds can also be mined from ‘alluvial deposits’ or sand, gravel and clay that has been transported by water erosion and deposited along either the banks of a river, the shoreline or on the ocean floor. 

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 sorted and valued according to their colour, size and quality. The best stones enter the gem market and any that are left are used in industry.

Cutting and polishing

The main hubs for cutting and polishing are India and China, as well as South Africa and Belgium. After they are polished, diamonds are once more categorised by their cut, colour, clarity and carat weight (the four c’s). The gems are then sold to wholesalers. 

Many diamonds, even those that are considered conflict-free, are cut and polished in sweatshop conditions, often by children, for very 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

After cutting an polishing, most diamonds are 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. 

Traceability & Ethical Diamonds

Because of the complexity of the conventional diamond supply chain, most jewellers do not know where there diamonds come from, whether they really are conflict-free, or whether they were cut and polished in sweatshop conditions.

At Ingle & Rhode we source only ethically produced, traceable diamonds. Find out more about our ethical diamond sourcing

No comments:

Post a Comment