The 4C's of Laboratory-Grown Diamonds — What's Different and Why It Matters

19 June 2026 · By Johan Poggenpoel · 1 min read

Did you know there are over 20,000 possible combinations of the basic diamond specifications: colour, shape, clarity and cut?

It can be overwhelming.

But it doesn't have to be.

You've probably come across the 4C model before — it's the standard framework for understanding what makes a diamond valuable, beautiful, and worth your money. But here's what most guides won't tell you: laboratory-grown diamonds don't always play by the same rules.

The 4Cs still apply, but how they behave — and what they mean for your budget — is different enough to warrant its own explanation.

That's what this is.

By the end you'll have a clear handle on each of the four characteristics, how they affect appearance, quality and price, and exactly where lab diamonds diverge from their mined counterparts.

The 4 Characteristics are:

Carat
Colour
Clarity
Cut-Grade

There are a handful of differences worth noting when you're weighing up mined diamonds against laboratory-made ones.

The winner?

Trickier than you'd imagine.

What are laboratory-made diamonds?

Until recently, Mother Earth had sole rights to the creation of diamonds.

She takes her time over a few million years to bake them in the Earth’s crust under immense pressure and heat. When ready; they’re mined, cut into polished gemstones, and masterfully set into high-end engagement rings and all sorts of coveted jewellery items.

And then, as if an Alchemist’s prayers were answered, a process to make real diamonds in a laboratory was discovered.

Using the same ingredients as Mother Earth, laboratories can mimic and greatly expedite the natural diamond formation process from millions of years to months.

This process yields true and real diamonds with their characteristic crystal structure, sparkle, fire and durability.

Demand for them is growing by the day for many reasons. Since they;

Share the identical molecular structure and composition of natural diamonds.
Are visually indistinguishable from naturally formed diamonds.
Cost a fraction of a similar natural diamond.
Are independently graded by leading diamond grading laboratories including the venerable GIA.
Are real diamonds and, as expected, test as such on digital diamond testers.

The C’s

First C: Carat – Weight.

Carat is simply a measure of weight, like kilogram and pounds, used in the jewellery industry.

It’s as simple as – 1,00 Gram = 5,00 ct (carats).

As the weight of a diamond increases, its price spikes parabolically.

A 1,00ct I VS1 mined diamond will set you back around R45 000. A 2,00ct mined diamond of the same quality - around R200 000. So double the weight - quadruple the price.

Lab diamonds don't follow this math. Prices are close to linear. Currently a 2ct lab diamond will cost just over double that of a 1ct similar specification stone.

Importance of weight

There’s no way around it. Close to every single diamond engagement ring design ever imagined looks better with a larger diamond.

It matters.

That’s why most of the diamond ring designs you find online and in print advertising are displayed with a beyond average size centre diamond to make the design look as impressive as possible.

Laboratory-made diamonds cost a fraction of their mined diamond counterparts and this significantly lower floor price makes attractive, Pinterest worthy, larger diamonds accessible across the board.

That’s a major draw for an ever-growing slice of the laboratory-grown diamond jewellery market.

Second C: Colour.

A diamond’s colour grade indicates how white or yellow a diamond is.

Using the common alphabet the colour range starts at D which is perfectly colourless, and tapers down to Z which is prominently yellow or brown.

As you move from one letter to the next the prominence of the colour tint very slightly intensifies.

Although not as dramatic as carat; the higher the colour, the rarer the diamond and the steeper the price.

When diamonds are made in a laboratory, the colour can be controlled to a certain extent, and as you would expect, laboratories focus on creating high-end, striking white diamonds.

The bulk of laboratory-made diamonds sold in the jewellery market are desirable top tier colours typically in the D – E – F – G – H colour range.

That’s without a doubt whiter than your average run of the mill natural diamond colours you find in engagement rings.

With lab diamond prices where they are I don't see any reason to not stay in the colourless (D-E-F) range.

Third C: Cut (Regardless of size, this is the most important C)

Diamond cut is often confused with the diamond shape (Round, oval, square).

The Cut grade refers to how well a diamond was cut and polished from uncut/rough to maximise its characteristic life, sparkle and brilliance.

A diamond has very special light reflection and refraction characteristics. You can think of a diamond’s facets (sides) as internal mirrors that reflect light internally to and from the diamond’s environment.

To optimise this light show – the ideal angles, dimensions, proportions of every facet have been determined. During grading a diamond is 3D scanned and compared to this benchmark range of values.

If the diamond has been poorly made the size, clarity and colour don’t matter… You’re stuck with what looks like a dull piece of glass.

In the world of naturally formed diamonds, the GIA is the benchmark of truthful, consistent third-party diamond grading. They developed a now popular 5 tier scale to grade a diamond’s cut grade;

Excellent: Optimal light reflection and refraction.
Very Good: Very close to perfect – mostly indistinguishable from Excellent cut unless you know your diamond very well.
Good: Some look nice, most don’t. Not recommended.
Fair: Not recommended.
Poor: Not recommended.

Currently, the vast majority of laboratory-made diamonds are graded by the IGI which does a great job but uses a slightly different cut grading system.

I don’t think it’s more than linguistics in an effort to differentiate themselves.

Where GIA’s top cut tier is Excellent, the IGI adds a tier above that is called “Ideal”.

In my opinion, it’s not superior to the Excellent cut as defined and issued by the GIA.

Whether you opt for GIA’s Excellent, or IGI’s Excellent or Ideal cut – you’re buying the cream of the crop.

Fourth C: Clarity

The clarity grade is a measure of the pureness of a diamond.

Both natural and laboratory-made diamonds do have certain inclusions/imperfections in them.

Inclusions vary greatly in type, severity, colour and location.

These range from benign minuscule white spots to cracks that severely compromise the strength of a diamond. And everything in between.

These inclusions leave every diamond with its own unique fingerprint.

The clarity grade is determined by a gemologist viewing and judging the type and amount of inclusions visible in a diamond at 10X magnification.

They’re not graded by the naked eye and often these inclusions are impossible to spot without magnification.

After inspection the gemologist issues a clarity grade based on what they saw;

Internally Flawless: No visible impurities under 10X magnification
VVS: Very, very small inclusions barely visible under 10X magnification
VS: Very small inclusions visible under 10X magnification.
SI: Small inclusions that might be visible to the naked eye.
I: Very obviously included to the naked eye.

Eye-clean is all you need.

With lab diamonds, you no longer have to play the "how low can I go" clarity game. Eye-clean is within easy reach without the usual trade-off gymnastics.

87% of women polled have a strong preference for diamonds free from any visible inclusions to the naked eye. That doesn't mean the diamond should be internally flawless — VS2 and higher is typically eye-clean and all you need to ensure your ring is absolutely blemish-free to anyone looking at it.

Rather put that budget toward a larger diamond than chase clarity grades your eye will never benefit from.

For sizes over 2,00ct, VS1 and higher is the safer bet.

As with colour, lab growing facilities focus on producing diamonds at the upper end of the clarity scale — and the vast majority come out cleaner than what you'd typically find on the natural diamond market.

Sounds interesting?

We're diamond professionals who've watched the reaction to lab-grown diamonds shift dramatically — and the value on offer right now is genuinely remarkable. More than a few couples who walked in undecided have walked out with a significantly larger stone than they thought possible.

I'm not here to push you one way or the other. What I will say is that if you haven't seen a lab-grown diamond in person yet, you owe it to yourself to take a look before you decide.

You can reach my studios here: