By wespellham October 14, 2025 - 2:47am

You know, I’ve been in the jewellery trade for close to two decades now, and if there’s one question that’s been coming up almost weekly lately, it’s this:“What’s better — IGI or GIA for lab-grown diamonds?”

It’s a fair question, and honestly, a few years ago, I would’ve given you a quick answer. But the truth is, things have changed — a lot. The world of lab made diamonds has grown so fast that even we jewellers have had to keep up with new grading standards, lab technologies, and consumer expectations.

So if you’re in the market for a sparkling new engagement ring, or you’re just curious about what all this IGI vs GIA talk is about, let’s take a proper look at what’s really going on behind those little certificates that come tucked with your diamond.

First things first — what are lab grown diamonds, really?

Before we get tangled up in acronyms, let’s start with the basics.A lab-grown diamond is, in every physical and chemical sense, a real diamond. It’s made of pure carbon, just like one pulled from deep underground. The only difference is where it’s formed — one grows under the earth over billions of years, and the other grows in a lab, in just a few weeks.

Now, the process isn’t as sci-fi as it sounds. Using either HPHT (High Pressure High Temperature) or CVD (Chemical Vapour Deposition), scientists recreate the exact conditions that form natural diamonds — the kind of heat and pressure that would crush most materials. The result? A diamond so identical that even a professional jeweller often needs specialised equipment to tell them apart.

And here’s what surprised even me when lab diamonds first started gaining popularity: they’re not “fake” or “synthetic” in the sense people used to think. They’re not cubic zirconia or moissanite — they’re real diamonds, just with a different origin story.

If you’re curious about the details, this article on lab made diamonds

dives into the science and ethics behind them — and it’s worth a read if you want to understand why so many Aussies are making the switch.

Why grading matters — and why it’s confusing

So, you’ve picked out a diamond that catches your eye. Whether it’s mined or lab-grown, that sparkle is everything. But here’s the tricky part: how do you know what you’re actually getting?

That’s where grading labs come in — the GIA (Gemological Institute of America) and the IGI (International Gemological Institute) are two of the biggest names in the industry.

Their job is to evaluate a diamond’s 4Cs — cut, colour, clarity, and carat weight — and issue a certificate that tells you exactly how your stone measures up.

Sounds simple, right? Well… not quite.

You see, GIA and IGI both have their own slightly different methods and grading philosophies. And when it comes to lab-grown diamonds, those differences have become a bit of a talking point in the jewellery world.

The GIA legacy — and its cautious approach

Let’s start with the GIA, because they’ve been around for almost a century. They’re like the gold standard of diamond grading — the institute that actually invented the 4Cs system in the first place.

For natural diamonds, a GIA certificate is as reputable as it gets. But when lab-grown diamonds first entered the scene, GIA wasn’t exactly rushing to embrace them. For years, they even avoided giving lab diamonds the same kind of grading reports they gave natural ones.

Instead, they’d use vague language like “laboratory-grown diamond” without offering the full 4Cs. The reasoning? They wanted to keep natural and lab diamonds clearly separated in the market.

That all changed around 2019, when GIA finally decided to update its system and start grading lab-grown diamonds using the same criteria as natural ones.

Even so, GIA’s approach is still conservative. Their grades tend to be strict — meaning a diamond graded “F” for colour at GIA might come back as “E” at another lab.

And honestly, that’s both a blessing and a curse. On one hand, you can trust that a GIA report is consistent and precise. On the other, if you’re comparing two lab-grown stones side by side, one with a GIA cert and one with IGI, the IGI one might look better on paper even though they’re visually identical.

IGI’s rise — and why jewellers love it

Now, the IGI has taken a different route altogether.

IGI was one of the first major labs to fully embrace lab-grown diamonds, long before GIA came around. They saw the trend early — and they decided to make the grading process faster, more accessible, and (frankly) more affordable.

Their certificates are easy to read, and they tend to be just a touch more lenient in grading. That’s not necessarily a bad thing, but it’s something buyers should understand.

An IGI-graded lab diamond with a “D” colour might be equivalent to a GIA-graded “E.” Tiny differences, sure, but ones that can affect pricing.

Here’s the thing though — and I’ll say this from experience — most jewellers, including many here in Australia, actually prefer IGI for lab-grown diamonds. Why? Because their reports are detailed, digital-friendly, and globally recognised. And since lab-grown stones are already far more affordable than natural ones, the IGI route helps keep prices competitive without compromising on transparency.

If you’d like a more technical side-by-side breakdown of the two labs, I’d recommend reading igi vs gia lab grown

— it’s one of the clearest, most balanced comparisons out there.

A quick story from the showroom

Let me tell you about a couple who came into my shop in Sydney a few months back. They were after an engagement ring — she wanted something classic but ethical, and he was mainly focused on value and quality.

We showed them two stones, both around 1.5 carats, both CVD-grown, both absolutely stunning. One had a GIA report; the other, an IGI.

Visually? They couldn’t tell them apart.

But the GIA diamond was about 10% more expensive — not because it was better, but because the GIA name carries that extra weight in the industry.

In the end, they went with the IGI stone, and when we set it into a platinum solitaire band, it looked every bit as spectacular as any mined diamond I’ve ever sold.

That’s when it really hit me — the gap between these labs isn’t about quality anymore. It’s about branding, perception, and how the industry is evolving.

The grading gap is closing

What’s encouraging is that both labs are learning from each other.

Over the past few years, IGI has tightened its standards significantly, while GIA has become more transparent and approachable with lab-grown diamonds.

Today, the difference between the two is often negligible for everyday buyers. Unless you’re a collector or an investor looking at resale values decades down the track, either certificate gives you confidence that your diamond has been properly assessed by a reputable body.

It’s also worth noting that both IGI and GIA laser-inscribe their diamonds with serial numbers that link directly to the certificate — something that gives buyers peace of mind, especially when shopping online.

What really matters when buying lab-grown

Here’s the truth no one likes to admit: most people will never notice the subtle differences in grading between IGI and GIA. What they do notice is the cut, the sparkle, and how that diamond makes them feel.

When it comes to lab-grown diamonds, you’re already getting incredible value — often 60–70% less than a mined equivalent, with none of the environmental baggage.

The key things to focus on are:

• Cut quality — this is what makes your diamond truly shine.

• Certification — whether IGI or GIA, just make sure it’s genuine.

• Reputation of your jeweller — go with someone transparent about sourcing and grading.

• How it looks to you — sometimes an “E” colour diamond looks no different to a “G” unless you’re under a jeweller’s loupe.

So, while “IGI vs GIA” debates make for good blog headlines, in practice, what matters is how your diamond performs in real life — on your hand, in natural light, and in those moments that actually count.

The emotional side of lab-grown

Something else I’ve noticed — and I didn’t expect this — is that many people feel a deeper sense of pride wearing a lab-grown diamond.

There’s something meaningful about choosing a piece of jewellery that’s ethical, traceable, and made with modern technology rather than mining. For some, it’s about sustainability; for others, it’s just the smart, forward-thinking choice.

I’ve even had customers who work in tech or science say they love the idea of wearing a diamond born from human innovation rather than nature’s chaos.

And I get that. There’s a story in that — a kind of quiet symbolism that feels right for our times.

My take as a jeweller

So, if you ask me whether to choose IGI or GIA for your lab-grown diamond, here’s my honest answer:

Go with whichever gives you confidence — but don’t overthink it.

If you’re the kind of person who values legacy, precision, and tradition, a GIA-graded stone might give you that extra reassurance. But if you care more about accessibility, value, and innovation, IGI is perfectly reputable — and in fact, leading the charge when it comes to lab-grown grading.

Either way, both are excellent choices. The real win here is that lab-grown diamonds have brought incredible transparency and affordability to an industry that’s often been anything but.

A final thought

Every diamond — whether it comes from deep within the earth or from a laboratory in Antwerp — carries a story.

For me, the shift toward lab-grown stones represents something much bigger than a market trend. It’s a reflection of how our values are changing — toward sustainability, technology, and a more conscious kind of luxury.

So, when you’re comparing IGI vs GIA lab grown reports, just remember: the certificate is a tool, not the story. The story is what that diamond means to you — how it marks your milestones, how it catches the light when you move your hand, and how it connects you to someone or something special.

And that, no matter what lab’s name is printed on the report, is what truly gives it value.

Written by:Daniel Walsh – Independent Jeweller & Diamond Consultant, Sydney

(If you’d like to learn more about diamond grading or sustainable jewellery options in Australia, feel free to reach out — I’m always happy to help people make informed, confident choices.)