Formation

Diamonds obtain their unique and beautiful structure deep inside the earth from extreme heat and pressure, beginning 3,3 billion years ago. The carbon atoms within the diamond bond into pyramidal structures, making them among the hardest minerals on Earth. Given the immense time it takes for a diamond to be formed, the following stages are more important to the global supply chain.

Exploration

Diamonds are found all over the world with companies investing in exploration, always looking for new, substantial sources of diamonds. The main diamond producing countries are Angola, Australia, Botswana, Canada, Democratic Republic of Congo, Namibia, Russia, and South Africa.

Mining

Once diamonds are detected, there are different types of mining operation used to extract them depending on the environment in which they are found. The majority of diamonds are extracted on an industrial scale by:

• open pit mining (excavation to reach diamonds on the surface of the ground) and
• marine mining (excavation of diamonds from the seabed).

Following extraction, the ore containing the rough diamonds goes through many stages of crushing and processing before it can be sorted and classified.
Diamonds are also extracted from alluvial deposits, where they are removed from sand, gravel and clay that has been naturally transported by water erosion and deposited along either the banks of a river, the shoreline or on the bed of the ocean. This process is called alluvial mining and is undertaken on an industrial scale by:

• coastal and inland mining (removal of overburden, such as sand and soil, to find diamonds) and
• marine mining (excavation of diamonds from the seabed).

Diamond mining on a non-industrial scale is undertaken involving individuals, families and communities and using the most basic equipment, such as sieves and pans – this is known as artisanal mining.

Sorting

Once processed at the mine, rough diamonds are delivered to sorting experts to be sorted and valued into different categories in preparation for sale. There are thousands of different categories into which diamonds can be sorted, dependent on size, shape, quality and colour. The majority of diamonds fall within a range of standard colours from colourless to faint yellow or brown tints. Some very rare diamonds, known as ‘fancies’, are bright colours, such are pink, blue or green. A perfectly transparent diamond with no colour or hue is considered to be the purest, but all rough diamonds have some distinguishing marks, known as inclusions, which make each one unique.

The best quality diamonds in terms of colour and clarity are distributed to the gem market with an accompanying Kimberley Process certificate to prove that they are from conflict free sources6. The remainder is used for industrial purposes, such as cutting and drilling.

Cutting & Polishing

Gem quality diamonds are usually distributed to one of the main diamond cutting and trading centers in Belgium, India, Israel, USA, China, Thailand and South Africa. Once they arrive at the diamond centers, experts (known as ‘diamantaires’) cut and polish the rough diamonds into shapes, such as the round brilliant, oval, pear, heart and emerald cuts. Polishing follows cutting, before the diamonds are again classified by their cut, colour, clarity and carat weight – also known as the ‘Four Cs’.

Jewellery Manufacturing

Wholesalers or manufacturers buy amounts of unset, polished diamonds. Wholesalers sell these to jewelry designers, manufacturers or retailers. Manufacturers will produce diamond jewelry designed and commissioned by a retailer or other jewelry designer. They may also create jewelry, designed by in-house teams, and sold direct to retailers. The System of Warranties is used as a declaration on the invoice for each transaction of polished diamonds to assure industry purchasers and consumers that their diamonds are from conflict free sources.

Retailing

The final stage of the diamond pipeline is when diamond jewelry is sold by retailers to the consumer.