You are torn between a lab-grown diamond and a mined one. You go looking for a comparison. You find two camps. On one side, natural diamond houses talking about rarity and value. On the other, lab-grown brands talking about ecology and price. Both pitches are self-interested. Here is ours, including what suits us and what does not. We sell lab-grown diamonds. So you will also learn what they do not solve.

The only real difference between a lab-grown diamond and a natural diamond

Let us start with the basics, because they often get buried.

A diamond is pure carbon crystallised in a cubic structure. That definition says nothing about where it formed. A lab-grown diamond fits it exactly. It has the same hardness, the same refractive index, the same density, the same brilliance. It is not an imitation.

That is what sets it radically apart from cubic zirconia or moissanite. Those two stones are different materials, with different optical properties. A lab-grown diamond, on the other hand, is a diamond. The distinction is legal as much as gemmological: in France, the rules simply require it to be named as such, and never sold as a mined diamond.

So the only real difference is origin. One stone formed in the Earth's mantle one to three billion years ago. The other formed in a reactor in a few weeks. The rest of the debate flows from that sentence and nothing else. If you want the details of the process, we explain them in what is a lab-grown diamond.

Lab-grown diamond prices: the gap, and why it keeps moving

It is the argument you hear most often, and also the most unstable one. Let us be precise.

For the same characteristics, a lab-grown diamond costs considerably less than a mined diamond. The gap has widened year after year, because global production capacity has grown faster than demand. An order of magnitude often seen today: a fraction of the price of a mined equivalent, and that fraction is still shrinking.

What this gap changes in practice. On the same budget, you get a bigger stone, a cleaner one, a better cut one, or all three at once. A fancy colour, blue, green, pink or yellow, becomes within reach, whereas in a mined stone it belongs in a museum.

What this gap does not change. The metal. On a finished ring, the stone is no longer the main cost when it comes from a lab. Recycled 18k gold, however, follows the world gold price. That is why the same design goes from a few hundred euros in 925 silver to several thousand in gold. The stone is identical. The setting makes the difference.

A second point few sellers mention. Lab-grown diamond prices are falling. That is excellent for today's buyer. It is bad for the idea of keeping the stone as a store of value. Both sentences are true at the same time.

Resale value: the question nobody tackles honestly

This is where we go against our own commercial interest.

A lab-grown diamond has practically no resale value. The second-hand market barely exists, and new prices are falling, which pushes used values down even further. If you are buying a stone with the idea of selling it one day, this is not the right product.

Now, honesty demands the second half of the sentence. A mined diamond does not resell well either. Between the shop price and what a professional offers to buy it back, the markdown is brutal and has always been well known. Private sellers who have tried it know. A mined diamond holds its value better in percentage terms, but it starts from a much higher purchase price.

The practical upshot. A piece of jewellery is not an investment, whatever the origin of the stone. The only part of your ring that keeps a material value is the metal. Recycled 18k gold is worth its weight in gold, yesterday as tomorrow. It is also the only line on your invoice that can be melted down. We explain what the hallmark guarantees, and what it does not, in our article on the 750 hallmark on your jewellery.

If resale value is your main criterion, buy gold and very little stone. If it is the piece of jewellery you want, resale is a false problem: nobody resells an engagement ring.

Reading an IGI report and spotting the "laboratory grown" wording

One legitimate doubt keeps coming up: how can you be sure of what you are buying, whichever way round?

The answer lies in the laboratory report. Our stones are certified by the IGI, the International Gemological Institute. A report gives the weight, colour, clarity, cut proportions, fluorescence and measurements. On a lab-grown stone, it also carries an explicit statement such as laboratory grown and specifies the growth process.

Three useful reflexes when you receive a report.

Check the number online. Every report has a number you can look up in the laboratory's database. A certificate that cannot be checked online is worthless.

Look for the girdle inscription. Most lab-grown stones carry a microscopic laser inscription on the edge, repeating the report number and a statement that the stone was grown in a laboratory. It is invisible to the naked eye and readable under a loupe.

Compare the measurements. The report gives the dimensions to a hundredth of a millimetre. They must match the stone in your hand. It is the simplest check against a substitution.

One last point to watch, valid for both origins. A mined diamond may have been treated, with fracture filling or high-pressure treatment to improve its colour. A good report mentions these. Always read that line.

Can you tell a lab-grown diamond with the naked eye?

No. And that is not a sales line, it is the reality on the ground.

Nobody can tell the difference by eye, not even an experienced jeweller. The two stones have the same composition, so they behave the same way optically. There is no different reflection, no colder sparkle, none of the signs some articles describe.

The diamond tester you see online is useless here. It measures thermal conductivity. So it says "diamond" for a lab-grown stone, exactly as it does for a mined one. All it can detect is an imitation, cubic zirconia or moissanite depending on the model.

Telling them apart requires laboratory equipment: spectroscopy, fluorescence imaging, analysis of growth patterns. It is a gemmologist's job, not a parlour test. In practice, the certificate is your only reliable tool. We have devoted a full article to the subject: how to identify a lab-grown diamond.

One consequence to accept. If you give a ring set with a lab-grown diamond, nobody will see it. Not the family, not the colleagues. That may come as a relief or bother you, depending on how you feel about it. But it is a fact, and it is better to know it beforehand.

Natural does not mean ethical, and neither does lab-grown

This is where both camps exaggerate the most. Let us go over it calmly.

What a lab-grown diamond genuinely avoids. No mine, so no earth moved on the scale of a mining operation, no tunnels, no mining working conditions. Traceability is simple: we know which reactor the stone grew in. It is a clear advantage, and a verifiable one.

What it does not avoid. A reactor uses a lot of energy, over several weeks. The real footprint therefore depends entirely on the electricity mix of the producing country. A stone grown with very carbon-intensive electricity is nothing to boast about. Few brands publish this information, and that needs saying.

What "recycled" guarantees, and what it does not. Our 18k gold is recycled. That means it comes from metal already in circulation, melted down and refined, rather than from new mining. It does not mean we know the full history of every gram. Recycled gold is by nature a mix. It is a serious improvement, it is not perfect traceability, and we would rather write that than let you believe otherwise.

The mined diamond side. The Kimberley Process regulates the trade in conflict diamonds, but it says nothing about working conditions or the environmental impact of a mine. A mined diamond certified as compliant is therefore not automatically an ethical diamond.

The honest conclusion is uncomfortable for everyone: neither supply chain is neutral. Lab-grown moves the problem from the earth to energy. We go through the numbers in our article on the environmental impact of both supply chains.

How to decide, based on what you are really buying

Enough principles. Here are some concrete cases.

An engagement ring on a set budget. Lab-grown wins comfortably. You get a more generous, better graded stone, in a recycled 18k gold setting rather than a compromise on the metal. It is the most obvious use case.

A coloured stone. Lab-grown wins hands down. A saturated blue, green, pink or yellow is extremely rare in a mined stone. The lab simply makes these colours available.

A pair of earrings. Lab-grown wins for a technical reason: you need two matched stones, same dimensions, same shade. With mined stones, matching is expensive and takes time.

A piece to hand down, meant for a family story. Here, the question is not technical. If an origin in the earth matters to you or to the person who will wear it, no price argument will replace that feeling. Own the choice of a mined stone, or pick a reused antique piece.

A purchase intended as a store of value. Neither. Buy metal, and an honest weight of it. We say so even though it sells us nothing.

To compare the settings and stones available, our ring collection brings all our designs together.

Key takeaways

Both stones are diamonds. The difference is origin, and nothing else in physical terms.

Lab-grown gives you more stone for your budget, makes colours accessible and is easy to trace. It does not give you resale value, and its footprint depends on electricity that few brands document.

Mining gives you a geological story and a slightly less brutal markdown on resale. It gives you neither an automatic ethical guarantee nor any visible superiority.

Our position, plainly. We chose lab-grown diamonds and recycled 18k gold because it is the best compromise we know how to defend today. We do not claim it is perfect. A house that swears its product has no drawbacks is selling you a pitch first.

To go further. The process is explained in what is a lab-grown diamond. The vocabulary of claims is taken apart in ethical jewellery. And to set a budget colour by colour, see the price of a coloured diamond.

FAQ

Is a lab-grown diamond a real diamond?

Yes. It has the same chemical composition, the same crystal structure and the same optical properties as a mined diamond. The only difference is its origin. Cubic zirconia or moissanite, by contrast, are different materials.

What is the price difference between a lab-grown diamond and a natural diamond?

For identical characteristics, a lab-grown diamond costs a fraction of the price of a mined diamond, and the gap keeps widening. On a finished ring, it is then the metal that makes the price difference, not the stone.

Does a lab-grown diamond have any resale value?

Very little, and you should know that before buying. The second-hand market barely exists and new prices are falling. That said, a mined diamond also takes a heavy markdown when sold back. Only the metal keeps a material value.

How can you tell if a diamond comes from a laboratory?

From the certificate. An IGI report carries an explicit statement such as laboratory grown and specifies the growth process. Most stones also bear a microscopic laser inscription on the girdle. No visual test can settle the question.

Does a diamond tester detect a lab-grown diamond?

No. A standard tester measures thermal conductivity and therefore shows diamond in both cases. It is only useful for ruling out an imitation such as cubic zirconia or moissanite.

Is a lab-grown diamond more eco-friendly?

It avoids mining and is easy to trace, which is a real advantage. On the other hand, growing it uses a lot of energy and its footprint depends on the electricity mix of the producing country. Neither supply chain is neutral.

Should you choose a lab-grown diamond for an engagement ring?

If your budget is set, yes: you get a more generous stone and a recycled 18k gold setting rather than a compromise. If an origin in the earth has strong sentimental value for you, no price argument will replace it.

Fiona