The complete diamond supply chain from mine to finger

Did you know the mining practice of a rough diamond started more than a 1000 years ago? But what’s even more fascinating is the fact that even after so many years the process of finding and distributing a rough diamond still remain relatively the same. Of course, the industry has progressed with the advancements made in technology and the machinery they use to mine, sort, cut and polish a diamond. But the stages of mining a diamond, up until it features on a bride-to-be’s ring finger, still relies on the personal touch and skilful eye of a human being. Here’s a complete look into some of the most important steps of the diamond supply chain:

Rough diamonds are mined before they can be sold to the manufacturer

Rough diamonds are mined before they can be sold to the manufacturer

The exploration and production of a rough diamond

Once a rough diamond has formed 150-200 kilometres below the earth’s crust it will be transported to the surface through kimberlite pipes – named after the South African town, Kimberley where the pipes were first discovered. Diamonds are found only in certain areas of the world, where diamond-bearing Kimberlite pipes were formed. Other than these Kimberlite pipes, diamonds may travel a great distance by river where alluvial mining takes place. Another source of diamonds is deep ocean, where stones are either carried by river to the ocean or Kimberlite pipes exist under water.

But with the ongoing demand for diamonds, the mining industry has spent more than R91 billion since the year 2000 in hope of finding new diamond deposits. The result? Only one big diamond deposit could be found in Bunder, India while a much smaller deposit was discovered in Botswana (known as the Karowe mine). Today, the majority of diamond exploration takes place in African countries such as the DRC, Zimbabwe and Angola. Once the diamonds are mined they will then be sold to the manufacturers. Today, South African countries produce the highest volume of diamonds worldwide.

The sales and distribution of a rough diamond

De Beers remain the biggest diamond suppliers in the world

De Beers remain the biggest diamond suppliers in the world

The growing demand for rough diamonds has increased since 2013. Today, the largest suppliers for these gemstones remain De Beers, followed by ALROSA. Other well-known suppliers of rough diamonds are SODIAM (Angola), Zimbabwe, Rio Tinto and the Dominion Diamond Corporation. But how exactly does the process work? De Beers sells most of their production using multi-year contracts (long-term agreement); they currently have more than 80 term contract clients, who they provide rough diamonds to. “We continued to see good demand across our product range in the second sales cycle, which was in line with expectations at this time of year. Sentiment remains positive heading into the Hong Kong International Jewellery Show this week – an important barometer of trade confidence,” Bruce Cleaver, CEO, De Beers Group. They also have an annual online auction where you could purchase diamonds online.

ALROSA, on the other hand, supplies a contract of three years to a selection of clients. They also offer a very competitive bidding and onetime sales to the trade. Other producers such as Gem Diamonds and Petra Diamonds only use an auction platform to sell their rough diamonds. But, most suppliers generally prefer term contracts with a selection of their clients, while offering an auction on larger stones. As soon as a rough diamond is purchased from the supplier it will undergo a cutting and polishing process by the jeweller.

The process of cutting and polishing a rough diamond

This part of the supply chain process requires technical skill and a trained eye to transform a rough diamond into a bedazzling gemstone. A process only a few jewellers master. Once it reaches this stage it’s important to keep the following five steps in mind:

PLANNING

It’s important to plan the cut and shape of the rough diamond

It’s important to plan the cut and shape of the rough diamond

A lot of planning is involved in the cutting and polishing process of a rough diamond. The reason for this is to avoid any unnecessary waste of the stone. During this step, the craftsman will mark the best possible cut and shape for a rough diamond by mapping the stone through a machine. With this detailed data and measurement, the cutter will have a clear idea on how to cut the diamond so it reaches its full potential.

CLEAVING

During this process the diamond will be cut into different pieces

During this process the diamond will be cut into different pieces

The cleaving process, also known as sawing, involves the cutting of the diamond into separate pieces; this way, the rough diamond slowly transforms into a beautiful faceted gemstone. The cutting of the diamond is one of the most difficult steps and requires a lot of knowledge and the right equipment.

BRUTING

The stone will undergo a bruting process to make it perfectly round

The stone will undergo a bruting process to make it perfectly round

Once the cleaving process is done, the rough diamond will undergo bruting, also known as girdling, to make the separate stones round. The cutter will do this by placing the stone on a spinning axle. During this step, two diamonds will rotate against each other to create a perfectly round shape.

POLISHING AND BLOCKING

The last stages of polishing the diamond involves two important steps namely, blocking and brillianteering

The last stages of polishing the diamond involves two important steps namely, blocking and brillianteering

The next step of the cutting and polishing process will be to form facets in the diamond. The polisher will start by placing the stone on a spinning wheel while being attached on a rotating arm. Once this step is completed the diamond will undergo two very important stages: blocking and brillianteering.

Blocking would involve creating a standard template for the rough diamond by polishing 8 pavilion main facets, 8 crown facets and 1 table facet. Then, during the brillianteering process, the remaining facets of the diamond would be added. To make sure the diamond reaches its full potential the stone needs to have 57 facets. When the facets are angled and aligned in perfect proportion, the stone will display incredible fire, brilliance and scintillation.

Learn more about the stages of diamond cutting and polishing.

INSPECTING AND CERTIFICATION

It’s necessary to inspect the diamond before it’s graded

It’s necessary to inspect the diamond before it’s graded

After the above steps are completed, the diamond will be sent for inspection. This way, inspectors can make sure that the diamond meets all the necessary standards before it is graded and certified according to the 4Cs of diamonds.

Manufacturing and sales of diamond jewellery

Jewellery can be bought in-store or online

Jewellery can be bought in-store or online

Loose diamonds are bought from wholesalers and various middlemen, before they are set in gorgeous jewellery pieces. These, in turn, are sold at retail level (online or through traditional brick-and-mortar stores) to the public and become symbols of love and commitment between two people.

Even though there are a number of steps and middlemen in the diamond supply chain from mine to finger, there are a select number of retail jewellers who source diamonds direct from the mine, cut and polish in-house and set diamonds into jewellery creations – thereby cutting out the middleman.

Next time you’re in the market to purchase diamond jewellery, consider the diamond’s journey from mine to finger; and the various stages, level of infrastructure and expertise required in getting the diamond to you.