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Roughly 250 tonnes of ore have to be moved to produce one polished carat.

That number does more work than any other sentence we could open with, and in Perth it lands differently than it would anywhere else in the country. A good share of the couples who sit down at our bench work in resources. When we say 250 tonnes, they do not picture an abstraction. They picture a haul truck, and then they picture how many of them.

This is the story of how a natural diamond gets from about 150 kilometres beneath the earth’s crust onto a hand, and what happens to it along the way. We set both natural and lab grown diamonds at our Mt Hawthorn studio and have no stake in talking either down. What follows is the actual sequence, with the numbers attached, including the ones the industry prefers to leave out.

Birth

A natural diamond’s story starts somewhere between one and 3.5 billion years ago. Before dinosaurs. Before anything walked.

Diamonds form in the earth’s mantle, between roughly 150 and 250 kilometres down, where carbon atoms sit under temperatures of 900 to 1,300 degrees Celsius and pressures somewhere between 45,000 and 60,000 atmospheres. Under those conditions carbon bonds into a cubic crystal lattice rather than the sheet structure that produces graphite. Change the pressure slightly and you get pencil lead instead.

Getting to the surface is the rarer event, and it has to happen fast. Volcanic eruptions drive molten rock up through kimberlite pipes at speed, carrying diamonds with them. If the ascent were slower, the carbon would have time to revert to graphite on the way. Almost every diamond you will ever see came up a pipe that erupted long before humans existed, which is a large part of why economically viable deposits are so few.

From there, weather does the rest. Rivers, wind and rain break down the host rock over millions of years and redistribute rough diamonds into gravels, riverbeds and eventually the sea. Which is why there are three quite different ways of getting them back.

Marine Mining

Rough diamonds carried to the coast by ancient river systems end up deposited on the seabed. Specialised vessels recover them by trawling and drilling the ocean floor, mostly off the coast of Namibia and South Africa.

It is the most technically demanding form of diamond recovery and produces some of the highest average quality rough in the world, because the journey to the sea destroys weaker, flawed stones along the way. What survives that trip tends to be good.

Alluvial Mining

The oldest method, and still the most widespread by number of people involved. Rough diamonds sit in the sand, gravel and clay of riverbeds and floodplains, and are recovered by sifting.

It is worth being clear that alluvial mining covers everything from large mechanised operations to artisanal digging by hand. The two have very different conditions attached, and the second is where most of the sector’s genuine human rights concerns sit.

Pipe Mining

The main commercial method. The kimberlite pipe itself is mined, either open-pit from the surface or underground once the pit reaches its economic depth.

This is where the 250 tonne figure comes from, and where another number belongs alongside it. Only about a quarter of all mined diamonds are gem quality. The rest go to industrial use, mostly abrasives and cutting tools. So the ore-to-ring ratio is considerably steeper than the headline number suggests.

Origin

The natural diamond industry has changed enormously in thirty years, and it is worth being accurate about how much.

Around 80 per cent of world supply now comes from Botswana, Canada and South Africa, all of which operate under enforceable regulation. The Kimberley Process, established in 2003, was designed to keep conflict diamonds out of the legitimate trade. It has substantially reduced that problem, and it is also narrower than most buyers assume, because its definition covers stones funding rebel movements against legitimate governments and does not extend to labour conditions or state-sanctioned abuses.

Traceability has improved considerably. Some producers now scan rough at the mine and carry a digital identity through every processing stage, so an individual stone can be followed from pit to polished. That technology is real and it works.

What it is not, yet, is universal. Plenty of rough still enters the market without that chain, particularly through the artisanal alluvial sector, and describing the whole industry as fully traceable overstates where it currently sits. When a stone we are offered carries verified origin documentation, we say so and we can show you. When it does not, we say that too. That distinction matters more than any general claim about the industry.

You will also see the natural diamond sector described as one of the world’s most sustainable industries. That description originates from the industry’s own marketing bodies. Diamond mining does support significant employment, infrastructure and health programmes in Botswana and Namibia in particular, and that is genuinely well documented. It also moves an extraordinary volume of earth. Both are true, and we would rather you weighed them yourself than took a slogan from us.

Back To The Community

Where the money goes is the part of this story with the strongest evidence behind it.

In Botswana, diamond revenue has funded a substantial share of national development since independence, including schooling and healthcare, through a long-running partnership between the government and the mining sector. Namibia operates a comparable model. These are not marketing claims. They are visible in national accounts.

There is a Western Australian chapter too, and it is closer to home than most people realise. The Kimberley region in our own north produced the mine that supplied roughly nine tenths of the world’s pink diamonds until it closed in November 2020, and it operated for decades alongside Traditional Owner agreements covering land access and employment. The Ellendale field in the West Kimberley produced yellow diamonds of exceptional colour. Western Australia is a diamond province, not just a market for them, which is a piece of context almost no jewellery article bothers to mention.

We hold Western Australian pink diamonds at the studio, and the supply will not be replaced. That scarcity is geological rather than manufactured, which is a rarer thing than it sounds.

Transformation

A rough diamond looks like a piece of frosted glass. Turning it into a gemstone is the point in the journey where human craftsmanship takes over from geology, and it is the stage we know best, because it is what happens at our own bench.

Globally, the overwhelming majority of cutting happens in India, and Surat in Gujarat handles the great bulk of it. The figure often quoted is that eleven of every twelve diamonds in the world’s jewellery pass through Indian cutting houses. The five stages below are broadly universal.

Step 1: Rough Scanning

No two rough diamonds are alike. Each stone is scanned to capture its exact geometry and internal features, generating a digital model and an identity record that follows it through every subsequent stage.

That record is what makes modern chain-of-custody possible. It is also worth understanding for what it is: a strong system of verification, not a guarantee. It confirms that the stone in front of you is the stone that was scanned. It does not by itself certify the conditions under which it was recovered.

Step 2: Rough Planning

There are effectively infinite ways to cut any given piece of rough, and the decision is a commercial one as much as an artistic one. Software models thousands of possible outcomes and weighs yield against quality.

This is where the invisible trade-off happens. A cutter can produce a heavier stone with weaker proportions, or a lighter stone that returns more light. Yield usually wins, which is precisely why cut grade varies so much between stones of identical weight, and why we tell every client to buy cut before anything else. Our 4Cs guide explains what that costs you.

Step 3: Sawing And Cleaving

Cutting the hardest natural material on earth requires either laser sawing or, in traditional cleaving, splitting the stone along its crystal plane with a single strike.

Cleaving is largely historical now, and for good reason. Diamond is hard but brittle along those planes, and a misjudged cleave destroys the stone outright. Laser sawing removed most of that risk, though the planning that precedes it still carries all the consequence.

Step 4: Final Planning

Before polishing, the planned proportions are checked once more against the model. Angles, symmetry and finish are confirmed, and the stone’s identity is revalidated.

This is the stage where a good cutter separates from an average one. Two stones of the same weight and clarity can differ by a full cut grade based on decisions made here, and that difference is visible across a room in a way that a clarity letter never is.

Step 5: Polishing

Polishing is the stage that produces everything you actually respond to in a finished stone. Facets are ground and polished against a rotating wheel charged with diamond powder, because nothing else will cut it.

This determines light performance: brilliance, meaning white light return, and fire, meaning the dispersion of light into spectral colour. A superbly cut stone in a modest colour grade will outperform a poorly cut stone two grades whiter, every time. When we assess a polished stone at the bench we look at how it behaves under three different lights before we look at the paperwork.

Once polished, the stone is graded and, above about 0.50 carats, certified. Then it reaches someone like us.

Heritage

This is where the article could easily slide into sentiment, so here is the concrete version.

A diamond is the oldest thing most people will ever own. It predates every mountain range you can name. It will outlast the setting we build for it, the building we build it in, and everybody reading this. That is not marketing. It is a material fact about crystallised carbon.

What it means for a ring is practical. On our bench we regularly unset stones from rings made in the 1970s and 1980s, rings that have been resized twice and retipped four times, where the metal is visibly thin and the design has dated badly. The stone comes out of the old mount looking exactly as it did the day it was first set. Roughly one in five rings we make now contains a stone that already belonged to the family, and that is the reason why.

Whether you choose natural or lab grown is genuinely your call, and we build both. What natural diamonds offer that lab grown cannot is age and scarcity. What lab grown offers is size and clarity for the money. We set out the comparison properly in lab grown versus natural diamonds and we will give you the same answer in person that we give in writing.

Frequently Asked Questions

The questions this subject raises most often at the counter.

How Long Does A Natural Diamond Take To Form?

Between one and 3.5 billion years, at depths of roughly 150 to 250 kilometres. A lab grown diamond of identical chemistry takes a few weeks.

How Much Ore Is Needed For One Carat?

Around 250 tonnes on average, and only about a quarter of what is recovered is gem quality. Both numbers vary enormously by deposit.

Where Do Most Natural Diamonds Come From?

Roughly 80 per cent of world supply comes from Botswana, Canada and South Africa. Most cutting happens in India, principally in Surat.

Are Natural Diamonds Ethically Sourced?

The honest answer is that it depends on the stone. The Kimberley Process has substantially reduced conflict diamonds but is narrower in scope than most people assume. Large regulated operations in Botswana, Namibia and Canada have strong documentation. The artisanal alluvial sector is far less consistent. Ask about the specific stone rather than the industry.

Is A Natural Diamond A Better Investment Than Lab Grown?

It holds value more predictably, though almost no engagement ring resells for what it cost. Certified fancy coloured stones behave differently and are covered on our investment stones pages.

Can I Trace My Diamond Back To Its Mine?

For some stones, yes. Several producers now provide verified origin documentation from rough scan through to polished. Many stones do not carry it. We will tell you which category yours falls into.

Does A Natural Diamond Look Different To A Lab Grown One?

Not to the eye, and not to a standard diamond tester, which reads thermal conductivity and returns the same result for both. Laboratories distinguish them using specialist equipment that reads growth patterns and trace elements.

Come And Hold One

You can read about 250 tonnes of ore. Holding the result is a different experience, and it is the reason we keep loose stones at the studio rather than ordering them in after a decision has been made.

Come to our Mt Hawthorn workshop and we will put natural and lab grown side by side under the same light, show you what a certificate does and does not tell you, and walk you through where each stone came from as far as the documentation allows. The bench behind the counter carries close to two centuries of combined experience, and master jeweller Paul holds two Jewellery Association of Australia Awards. The same team that handcrafts the Miss Universe Australia crown will set whichever stone you choose.

If you have an inherited stone sitting in a drawer, bring that too. It has already made most of this journey. It just needs somewhere better to finish it.

Browse our engagement rings, look through the custom gallery, or start shaping something with our bespoke ring builder.

Book a consultation and we will have stones on the bench when you arrive.