By Marten Ramon Cross, The Diamond Shoppe
The short answer
In South Africa right now, a 1 carat lab-grown diamond sells for roughly R5,500 to R15,000, while a comparable 1 carat natural diamond sells for R50,000 to R70,000 factory-direct — or R100,000 and up at a traditional retail jeweller. That is a price gap of around 80–90%.
The gap is real, and for some buyers a lab-grown is the sensible choice. But the price you pay is only half the question. The other half is what the stone is worth the day you try to sell it.
Here is our answer to that, and we are in an unusual position to give it because we buy diamonds back across our counter as well as selling them: we value a lab-grown diamond at zero. If one comes in set in a piece of second-hand jewellery, we weigh the gold and pay for the gold. The stone itself is worth nothing to us, and we do not buy them.
That is not a sales position. It is what the arithmetic of the market currently produces, and the rest of this
article explains why.
Why the price gap is so wide
A lab-grown diamond is a real diamond. It has the same crystal structure, the same hardness, the same optical behaviour as a mined stone. The difference is not quality — it is supply.
Natural diamonds of gem quality took roughly one to three billion years to form and exist in finite quantity. A 1 carat lab-grown diamond can be produced in a chamber in six to ten days by the HPHT method, or three to four weeks by CVD — and the number that can be made is limited only by how many chambers exist. Over the last eight years, a great many chambers were built.
The result is one of the fastest price collapses in the history of any luxury product. The Edahn Golan LGD Wholesale Price Index, which has tracked the category since July 2018, is down 96% over that period. Prices dropped 26% across 2025 alone, then a further 14% year-on-year in the first quarter of 2026.
As of September 2026, 1 carat lab-grown stones are trading in the wholesale market at around US$50 to US$80 per carat — roughly R800 to R1,300 at current exchange rates, before any setting, retail margin or VAT. They came down again in the last few months.
Retail prices have not fallen nearly as fast. Trade reporting puts lab-grown retail markups above 80% over wholesale cost, barely changed between 2025 and 2026 despite the collapse underneath. That is why the discount you are offered in a shop is a good deal smaller than the wholesale numbers would suggest, and why unsold stock is building up behind it: the US retail inventory-to-sales ratio for lab-grown has
climbed from single digits in 2020 to close to 50%.
What a 1 carat costs in South Africa today
| 1 CT LAB-GROWN | 1 CT NATURAL (FACTORY- DIRECT) | 1 CT NATURAL (TYPICAL SA RETAIL) | |
| Typical retail price | R5,500 – R15,000 | R50,000 – R70,000 | R100,000+ |
| Current wholesale | ~US$50–80 per carat | rises with rarity and size | rises with rarity and size |
| What sets the price | production capacity | rarity, cut quality, certification | rarity + retail markup chain |
| Price trend, last 3 years | down ~96% since 2018 | pressured, now recovering | pressured, now recovering |
| What we pay to buy it back | Nothing — gold value only | Traded in against an upgrade, every week | Traded in, but you carry the retail markup as a loss |
A lab-grown diamond is a real diamond. It has the same crystal structure, the same hardness, the same optical behaviour as a mined stone. The difference is not quality — it is supply.
Natural diamonds of gem quality took roughly one to three billion years to form and exist in finite quantity. A 1 carat lab-grown diamond can be produced in a chamber in six to ten days by the HPHT method, or three to four weeks by CVD — and the number that can be made is limited only by how many chambers exist. Over the last eight years, a great many chambers were built.
The result is one of the fastest price collapses in the history of any luxury product. The Edahn Golan LGD Wholesale Price Index, which has tracked the category since July 2018, is down 96% over that period. Prices dropped 26% across 2025 alone, then a further 14% year-on-year in the first quarter of 2026.
As of September 2026, 1 carat lab-grown stones are trading in the wholesale market at around US$50 to US$80 per carat — roughly R800 to R1,300 at current exchange rates, before any setting, retail margin or VAT. They came down again in the last few months.
Retail prices have not fallen nearly as fast. Trade reporting puts lab-grown retail markups above 80% over wholesale cost, barely changed between 2025 and 2026 despite the collapse underneath. That is why the discount you are offered in a shop is a good deal smaller than the wholesale numbers would suggest, and why unsold stock is building up behind it: the US retail inventory-to-sales ratio for lab-grown has
climbed from single digits in 2020 to close to 50%.
What actually happens when you try to sell a lab-grown diamond
This is the part almost nobody in the industry will put in writing, so here it is plainly.
We do not buy lab-grown diamonds. When one arrives — and they do arrive, usually set into a piece of second-hand jewellery someone is selling us for the gold — we weigh the metal, pay for the metal, and the stone is valued at zero.
What happens to those stones afterwards says everything. We take them out and keep them. They cost us nothing, so we give them away — in competitions, or as gifts to customers. There is no resale channel to put them through.
As far as I am aware, there is no retailer in this market buying lab-grown diamonds back second-hand.
That is not coordination between jewellers. It is arithmetic. A second-hand stone competes directly against new production, and new production keeps getting cheaper — currently around US$50–80 per carat wholesale. A buyer choosing between your two-year-old 1 carat lab-grown and a brand-new one selling for less than you originally paid has no reason to choose yours.
The certification problem compounds it. A second-hand lab-grown usually arrives with no paperwork, and the cost of certifying it is disproportionate to what it is worth — the stone’s entire wholesale value is a small
multiple of the assessment fee. On a natural stone, certification is a sensible percentage of value. On a lab-grown, it stops making commercial sense.
None of this is a claim about quality. The stones are identical to natural ones in every physical respect. It is
a claim about what a market pays for something that can be manufactured without limit.
Are lab-grown diamonds real diamonds?
Yes. A lab-grown diamond is chemically, physically and optically a diamond. It is not a simulant — cubic zirconia and moissanite are different materials that only resemble diamond. A lab-grown stone is carbon indiamond structure, and it will scratch glass, test as diamond on a thermal probe, and last as long as a mined stone.
Anyone who tells you a lab-grown is “fake” is either misinformed or selling you something. The honest distinction is origin and scarcity, not authenticity.
Can a jeweller tell the difference?
There is a second answer to this question that has nothing to do with equipment, and after years at the bench it is the one I find myself giving.
Lab-grown diamonds are boring. They are copy-paste material. They all look exactly the same — perfectly clean, perfectly white. I don’t get excited when I see one.
Show me a VS2 or an SI1 and I want to loupe it. I want to see where the inclusion sits. I want to see how
the stone has been cut, because a natural stone is never cut as perfectly — you cannot afford to waste the material, so the cutter works around what the rough gives him. There are always signs of the natural stone left in the finished piece.
The factories are now mass-cutting lab-growns, and it shows. Every oval looks the same. Perfect
proportions, perfect everything, and no character. Whereas with a natural fancy cut — an oval, a pear — the cutter had to approach that stone differently because of the shape of the rough.Every natural stoneends up with a character entirely its own.
One is copy-paste. The other is a unique item. That difference doesn’t appear on any certificate, and it is
most of what you are actually buying.
What GIA's grading change tells you
This matters if you are comparing certificates, and it is more recent than most buyers realise.
Since 1 October 2025, the Gemological Institute of America — the laboratory that created the 4Cs and grades the majority of the world’s important natural diamonds — no longer issues colour and clarity grades for lab-grown diamonds. It replaced that service with the GIA Laboratory-Grown Diamond Quality Assessment, which sorts stones into two descriptive categories: “Premium” and “Standard”, with no designation at all for stones that fall below a minimum standard.
GIA’s stated reasoning is that it will no longer use nomenclature created for natural diamonds to describe a manufactured product.
The practical translation: because lab-grown production clusters so heavily at the top of the colour and clarity scales, a grading system built to separate rare stones from common ones stops carrying information. When almost everything is a D VVS1, “D VVS1” tells you nothing worth paying for.
This is GIA’s third grading approach for lab-grown since 2006, and reports issued before the change
remain valid. But if you are weighing a lab-grown against a natural on the strength of a headline grade,
understand that the institution that invented that grade has decided it no longer means the same thing on
a manufactured stone.
Do natural diamonds hold their value?
Better, though nobody should pretend a diamond is an investment.
What I can tell you is what we see. We take natural stones back in constantly — usually as upgrades. Someone buys an 80-point oval engagement ring, comes back four or five years later, and we trade that stone in against something bigger, a better quality, or a different shape because they have changed their mind. There is always a market for it.
The thing that determines how much you get back is what you paid in the first place. If you buy right, you don’t lose anything like as much as you expect. If you bought on the high street, you take quite a hefty knock, because you are carrying the retail markup chain as a loss the moment you walk out of the shop.
The wider market is turning, and it is visible from inside the trade. After three years of depression in natural diamond prices, a lot of mines have closed. Right now there is a serious shortage of bigger, good-quality natural stones, prices for them are phenomenal, and the rough is very difficult to buy even if you want it. It
feels like a turning point.
The published figures agree. The RapNet Diamond Index for 1 carat natural stones rose 0.5% in August 2026, its first increase in fifteen months, with smaller sizes up more (0.30ct up 2.0%, 0.50ct up 2.5%). De Beers’ revenue fell 19% year-on-year in the first half of 2026 and Alrosa’s fell 36%, and both have cut production accordingly.
In fairness to lab-grown: after collapsing 96%, wholesale prices are showing early signs of a floor, with 1 carat rounds actually rising 1% in the second quarter of 2026 — the first positive movement in years. If lab-grown has bottomed, the losses ahead are smaller than the losses behind.
So when is a lab-grown the better buy?
There is a real answer to this, and it isn’t the one a natural-diamond seller is expected to give.
Lab-grown is genuinely good for statement jewellery. If you want something very out there — a big stone, properly blingy, the kind of piece people used to make with semi-precious gemstones — lab-grown is now the obvious material. You can do it in fancy yellows and other colours, and you can do really fun
things with it.
The economics are the whole argument. A piece that would cost you in the region of R1 million in natural stones can be done in lab-grown for something like R50,000 to R100,000, and it will look spectacular. For a piece that exists to be worn and enjoyed rather than held or passed on, that is not a close call.
A natural stone is the better choice when the purchase is meant to hold some value, be insured meaningfully, be traded up later, or be handed down. And when the emotional weight of the object matters — which, for an engagement ring, it usually does.
Where we sit, so you can weigh what you've just read
Yes, we do sell lab-grown diamonds. We don’t stock them, but we bring them in for customers who want them.
We don’t stock them for a reason. The scaling in that industry is unbelievable — we cannot keep up with how quickly prices are coming down, and I am not sure where it stops. My honest view is that lab-grown diamonds will end up used more for industrial purposes than for jewellery. Not right now, but in time.
The Diamond Shoppe has been trading since 1972, when my father started the business. We are second-generation, we source rough locally, we cut and polish it in our own factory in Cape Town, and we sell directly to the customer — which is why our natural pricing sits between R50,000 and R70,000 for a mid- range 1 carat against R100,000-plus at a typical retailer.
We also buy diamonds back. That is the part that gives us a view of what stones are worth after the sale, and not just before it.
Frequently asked questions
How much is a 1 carat lab-grown diamond in South Africa? Between roughly R5,500 and R15,000 at retail, depending on grade and setting. At wholesale, 1 carat lab-grown stones are trading at around US$50 to US$80 per carat as of September 2026. A comparable 1 carat natural diamond costs R50,000 to R70,000 factory-direct, or upwards of R100,000 at a traditional retail jeweller.
What is a lab-grown diamond worth if I sell it back? Nothing. At The Diamond Shoppe we value lab- grown diamonds at zero — if one comes in set in second-hand jewellery, we pay for the weight of the gold and the stone carries no value. We do not buy them, and as far as we are aware no retailer in South Africa is buying them back second-hand.
Do lab-grown diamonds hold their value? No. Resale value is effectively zero, because any second- hand stone competes against new production that keeps getting cheaper — currently around US$50–80 per carat wholesale. Natural diamonds retain considerably more, particularly if you bought factory-direct rather than at retail, though they are not an investment either.
Why are lab-grown diamonds so much cheaper than natural ones? Supply. Lab-grown diamonds can be produced in days to a few weeks in unlimited quantity, while gem-quality natural diamonds are finite.
Wholesale lab-grown prices have fallen 96% since 2018, though retail prices have not fallen nearly as far, with markups holding above 80% over wholesale.
Are lab-grown diamonds real diamonds? Yes. They are chemically, physically and optically identical to mined diamonds. They are not simulants like cubic zirconia or moissanite.
Can you tell a lab-grown from a natural diamond? Not by eye or with a loupe. We use a Yehuda Sherlock Holmes detector, which identifies a synthetic stone in seconds. Certified lab-grown stones are also laser-inscribed on the girdle.
Is GIA still grading lab-grown diamonds on the 4Cs? No. Since 1 October 2025, GIA has replaced colour and clarity grades for lab-grown diamonds with the GIA Laboratory-Grown Diamond Quality Assessment, which sorts them as “Premium” or “Standard” — on the basis that grading language built for natural rarity no longer carries meaning when most lab-grown production sits at the top of the scale.
When does a lab-grown diamond make sense? For statement and costume jewellery, where the point is visual impact rather than lasting value. A piece costing around R1 million in natural stones can be made in lab-grown for roughly R50,000 to R100,000 and will look spectacular. For an engagement ring intended
to hold value, be insured, traded up or handed down, a natural stone is the better choice.