Every year, roughly 118 million carats of rough diamonds are extracted from the earth. These extraordinary stones — formed billions of years ago in conditions of extreme heat and pressure far beneath our feet — travel an incredible journey before they reach the display case of a jeweller. But where exactly do diamonds come from, how are they mined, and what route do they take from remote mines to the heart of the Antwerp diamond district? This guide covers it all, with the latest 2024 production data and insights from our decades of experience in the trade.
How Are Diamonds Formed?
Diamonds are crystallised carbon, forged under extraordinary conditions deep within the Earth's mantle — typically at depths of **150 to 200 kilometres** below the surface. At these depths, temperatures exceed 1,000 °C and pressures reach 45 to 60 kilobars (roughly 50,000 times atmospheric pressure at sea level).
Under these conditions, carbon atoms bond in a rigid three-dimensional lattice structure — the same atomic arrangement that makes diamond the hardest known natural material on Earth, scoring a perfect 10 on the Mohs hardness scale. Most natural diamonds formed between **1 billion and 3.3 billion years ago**, making them some of the oldest materials ever held in human hands. To understand how these geological properties translate into value, see our guide to the 4 C's of diamond.
Diamonds form in the upper mantle and reach the surface through explosive kimberlite eruptions.
Diamonds don't stay buried forever. They reach the surface through rare, explosive volcanic eruptions that create vertical channels called kimberlite pipes — named after the South African town of Kimberley, where they were first identified in the 1870s. These eruptions are extraordinarily fast, travelling at speeds of up to 70 km/h, which prevents the carbon from converting back to graphite during the ascent.
Did you know? To extract just one carat of gem-quality rough diamond (0.2 grams), mining companies must process approximately 250 tonnes of rock, soil and sand. And only about 20% of all mined diamonds are suitable for jewellery — the remaining 80% are used for industrial applications like cutting, drilling and polishing.
Two Types of Diamond Deposits
Geologists distinguish between two main types of diamond deposits, and understanding the difference matters because it directly affects how diamonds are mined and what quality you can expect.
Primary (Kimberlite) Deposits
Primary deposits are the original source. Diamonds are found embedded in kimberlite (or, more rarely, lamproite) rock within the volcanic pipe itself. These deposits are typically mined through large-scale open-pit or underground operations. The world's most productive diamond mines — including Jwaneng in Botswana, Jubilee in Russia, and Venetia in South Africa — are all kimberlite mines. Primary deposits tend to yield a higher proportion of gem-quality stones, which is why countries like Botswana and Namibia produce some of the most valuable rough diamonds per carat.
Secondary (Alluvial) Deposits
Secondary deposits, also called alluvial deposits, form when diamonds are eroded from their original kimberlite host rock by millions of years of weathering. Rivers, streams and ocean currents transport the loose stones, eventually depositing them in riverbeds, floodplains, coastal gravels or even the ocean floor. Alluvial mining ranges from large-scale marine operations (like De Beers' fleet off Namibia's coast) to small-scale artisanal mining by individual workers in countries such as Sierra Leone and the Democratic Republic of Congo.
Where Are Diamonds Mined? Top Producing Countries (2024)
Diamond deposits have been discovered in over 35 countries, but commercial production is heavily concentrated. In 2024, just ten countries accounted for over 99% of global rough diamond output, according to the Kimberley Process Certification Scheme. Here are the leading producers:
| # | Country | Volume (M carats) | Value ($ B) | $/Carat |
|---|---|---|---|---|
| 1 | Russia 🇷🇺 | 37.3 | $3.34 B | $89 |
| 2 | Botswana 🇧🇼 | 28.2 | $3.31 B | $117 |
| 3 | Angola 🇦🇴 | 14.0 | $1.41 B | $101 |
| 4 | Canada 🇨🇦 | 13.3 | $1.08 B | $81 |
| 5 | DR Congo 🇨🇩 | 9.0 | $0.17 B | $19 |
| 6 | South Africa 🇿🇦 | 5.3 | $0.66 B | $124 |
| 7 | Namibia 🇳🇦 | 2.3 | $0.96 B | $417 |
Source: Kimberley Process Certification Scheme, 2024 data. Value per carat reflects average for all grades including industrial.Notice how volume and value don't always align. Namibia mines just 2.3 million carats — a fraction of Russia's output — yet its diamonds average $417 per carat, the highest of any major producer. This is largely because Namibia's offshore marine mining captures exceptional gem-quality stones that have been naturally sorted by ocean currents over millions of years.
For buyers, origin can influence both value and character. A diamond's cut quality, clarity, colour, and carat weight ultimately determine its beauty and price — but knowing where it was mined adds a layer of provenance and story.
How Are Diamonds Mined?
The method used to extract diamonds depends on the type of deposit. Modern diamond mining involves sophisticated technology, but remains one of the most resource-intensive processes in the mining industry.
Open-Pit Mining
Used for kimberlite deposits near the surface. Controlled explosions break up layers of rock, and heavy machinery transports the ore to processing plants. Botswana's Jwaneng mine — often called the richest diamond mine in the world by value — is an open-pit operation.
Underground Mining
When open-pit mines become too deep (typically beyond 600 metres), operations transition underground. De Beers' Venetia mine in South Africa recently completed this transition and is expected to remain productive through at least the 2040s.
Alluvial Mining
Along riverbeds and beaches, diamonds are extracted by sifting through gravel and sediment. This ranges from large mechanical operations to small-scale artisanal mining where workers use basic hand tools. Countries like Sierra Leone and the DR Congo rely heavily on artisanal methods.
Marine Mining
Off the coast of Namibia and South Africa, specialised vessels use crawler systems and suction pipes to vacuum diamond-bearing gravel from the seabed. Marine diamonds are often of exceptional quality because the ocean's natural sorting process concentrates the hardest, most intact stones.
A Brief History of Diamond Discovery
From Mine to Market: The Diamond Pipeline
A diamond's journey from the earth to your hand involves multiple stages across several continents. The industry calls this sequence the "diamond pipeline" — and Antwerp sits at its very centre.
- Mining — Rough diamonds are extracted from primary or secondary deposits across Russia, Botswana, Canada, Angola, South Africa, Namibia, and other producing nations.
- Sorting & valuation — Rough stones are sorted into over 16,000 categories based on size, shape, colour, and quality. Major sorting centres include Antwerp, London and Gaborone.
- Cutting & polishing — Skilled craftspeople transform rough stones into polished gems. The quality of the cut directly determines a diamond's brilliance, fire and sparkle. Leading cutting centres are Antwerp, Mumbai, Tel Aviv, and New York.
- Certification — Independent laboratories like GIA, HRD Antwerp, and IGI grade each stone on the 4 C's (cut, colour, clarity, carat) and issue a certificate guaranteeing its characteristics.
- Trading — The Antwerp diamond district handles approximately 80% of the world's rough diamonds and 50% of polished diamonds. The district's "Diamond Square Mile" is the global epicentre of the trade.
- Retail — Certified, polished diamonds reach consumers through jewellers and trusted dealers like Diamantwerp, who offer transparent pricing by connecting buyers directly to the Antwerp market.
Antwerp: The Diamond Capital of the World
No article about where diamonds come from is complete without mentioning Antwerp. For over five centuries, this Belgian city has been the undisputed centre of the global diamond trade. The Antwerp diamond district — concentrated around Pelikaanstraat, Hoveniersstraat and the surrounding streets near Antwerp Central Station — is home to more than 1,500 diamond companies, four diamond bourses, and several of the world's most respected grading laboratories including HRD Antwerp. Learn more about the role of HRD in our guide to the HRD diamond certificate.
The Antwerp World Diamond Centre (AWDC) oversees the district and promotes ethical trading practices. Read our in-depth look at the AWDC and its mission. In 2024, Antwerp processed over $30 billion worth of rough and polished diamonds — more than any other city on Earth. When you buy a diamond from Diamantwerp, you're purchasing directly from this storied marketplace, with full certification and transparent provenance.
Why Antwerp matters for buyers: Purchasing from an Antwerp-based dealer like Diamantwerp means access to the world's largest selection of certified loose diamonds at trade-level pricing — often 30–50% below traditional retail. Every stone comes with a GIA, HRD, or IGI certificate verifying its quality.
Ethical Sourcing & the Kimberley Process
The diamond industry has not been without controversy. In the 1990s, so-called "conflict diamonds" (or "blood diamonds") funded civil wars in Sierra Leone, Angola, and the DR Congo. The international community responded with the Kimberley Process Certification Scheme (KPCS), established in 2003, which requires participating nations to certify that rough diamond shipments are conflict-free.
Today, the Kimberley Process covers 99.8% of global rough diamond production across 85 participating countries. While not perfect — critics point out that the scheme's definition of "conflict" is narrow — it has dramatically reduced the flow of conflict diamonds. Additional safeguards include:
- Blockchain traceability — companies like Everledger and De Beers' Tracr platform create digital records tracking a diamond's journey from mine to retailer
- Responsible Jewellery Council (RJC) — an independent certification body that audits the entire supply chain for ethical and environmental standards
- GIA and HRD origin reporting — advanced spectroscopic analysis can now determine a diamond's geographic origin with high accuracy
At Diamantwerp, every loose natural diamond we sell is independently certified and sourced through the Kimberley Process. We work exclusively with established suppliers who adhere to the AWDC's Best Practice Principles.
For a complete guide to ethical diamond sourcing — including the Kimberley Process, RJC certification, and blockchain traceability — read our dedicated article: Ethical Diamonds: What You Need to Know
Natural vs. Lab-Grown Diamonds
In recent years, lab-grown diamonds have emerged as an alternative to mined stones. These are real diamonds — identical in chemical composition, crystal structure and physical properties — but created in laboratories using one of two methods: High Pressure High Temperature (HPHT) or Chemical Vapour Deposition (CVD).
While lab-grown diamonds offer a lower price point, they differ from natural diamonds in one fundamental way: rarity. A natural diamond took billions of years to form and made an extraordinary journey to reach the surface. That geological story, combined with independently certified provenance, is what gives natural diamonds their enduring value — both emotional and financial.
Whether you choose natural or lab-grown is a personal decision. If you'd like to understand the differences in more detail, explore our Diamond Journal for expert guides on choosing between natural and lab-grown stones.
What to Look for When Buying a Diamond
Now that you know where diamonds come from and the journey they take, here's what matters most when choosing your own stone:
- Certification first — Always insist on a diamond graded by an independent laboratory: GIA, HRD Antwerp, or IGI. The certificate is your guarantee of quality and authenticity.
- Understand the 4 C's — Cut affects brilliance most. Colour and clarity determine purity. Carat measures size. Our complete 4 C's guide explains each in detail.
- Choose the right shape — From the classic round brilliant to the elegant oval or geometric princess cut, each diamond shape has its own character and value proposition.
- Buy from a trusted source — An Antwerp-based dealer with direct market access can offer better selection and pricing than traditional retail. Contact our team for personal advice.
