I’ve been working around gemstones since I was barely tall enough to reach the polishing bench, and I’ll be honest with you—very little in the jewellery world has stirred up quite as much curiosity as lab diamonds. Not because they’re unusual or mysterious, but because people are finally realising they’re real diamonds, with the same potential for beauty, personality and brilliance as anything pulled from underground.
But here’s something you might not know: when it comes to sparkle, the magic isn’t just in the carbon. It’s in the cut.
The way a diamond is shaped, angled and polished has far more influence on its fire and brightness than most people expect. I’ve seen modest little stones absolutely come alive with the right proportions… and high-carat diamonds fall flat because they weren’t cut with love, skill, or, frankly, decent math.
So, if you’ve been hearing more about lab diamond cuts and wondering what actually sets them apart, you’re in the right place. Let’s wander through the world of facets, symmetry and light—without the robotic jargon, promise.
Why the Cut Matters More Than Anything Else
When a customer comes into the studio and says, “I want the sparkliest diamond you’ve got,” I always smile. Not because it’s an unreasonable request, but because it gives me the perfect excuse to talk about cuts.
Think of a diamond like a tiny hall of mirrors. Every facet has a job, and if even a single angle sits slightly off, the whole stone can lose its life. The cut determines how light travels through the diamond—how much is reflected back to your eye, how much disperses into those rainbow flashes we call fire, and how evenly the light dances when you tilt it in your hand.
The carat, colour and clarity matter too, of course. But no other characteristic controls beauty quite as dramatically as the cut.
This applies equally to natural diamonds and lab diamonds—and if you’re curious about exploring some DIY jewellery ideas or just want to get a better grip on their creative potential, this little guide offers a lovely starting point.
The Beauty of Lab Diamonds: A Cutter’s Dream
There’s something quietly delightful about cutting lab diamonds. They’re structurally consistent, meaning fewer internal surprises, fewer stressful inclusions and, for the most part, a more predictable path to a perfect polish. Some cutters even compare working with them to baking with high-quality flour—you’re just more confident the final product will rise the way it should.
Because lab diamonds start with such precision-grown crystals, cutters can sometimes achieve sharper symmetry and cleaner facet alignment, which ultimately leads to a stronger, livelier sparkle. And while that’s not to say every lab-grown diamond is automatically well-cut (trust me, I’ve seen some shockers), the potential is undeniably high.
The Shapes People Love—and Why They Matter
Before we talk specific grades, proportions and those nitty-gritty details gem nerds adore, let’s look at shapes. Shape and cut aren’t the same thing, although they often get mixed up. Shape refers to the outer silhouette; the cut refers to the craftsmanship and facet structure.
Here are the most common shapes you’ll encounter and what they tend to say about the wearer (take this lightly—jewellery is personal, not prescriptive):
Round Brilliant
If diamonds had a blockbuster star, this would be it. Round brilliants are engineered to maximise sparkle, thanks to their 57 or 58 facets. They’re classic, versatile, and suit just about any hand or setting style.
Oval
Oval cuts create a longer, more elegant shape that flatters the finger and often looks larger than its carat weight suggests. People who love ovals usually appreciate a softer, more romantic design language.
Emerald
This one’s all about sophistication. With long, sleek step facets, an emerald cut doesn’t sparkle so much as it glows in clean flashes of light. I’ve always said it’s the diamond for someone who doesn’t need to show off—they already know who they are.
Cushion
Soft corners, gentle curves. Cushions have this vintage warmth that feels timeless without being overly traditional. They’ve climbed the popularity charts in the last five years, especially with lab-grown stones.
Princess
Sharp, modern, symmetrical. Princess cuts are brilliant performers, literally and figuratively. They pack a ton of sparkle and suit geometric or contemporary settings.
Pear, Marquise & Heart
I group these together because they’re what I’d call expressive shapes—each with its own emotional flair. When someone chooses one of these, they’re usually drawn to jewellery that feels meaningful, unique or playful.
If you’d like an expert-level dive into how each cut actually works (facet patterns, symmetry details and all), this guide breaks it down beautifully.
Understanding Cut Grades: What the Terms Actually Mean
People often assume “Excellent” or “Ideal” are marketing terms. They’re not—well, not entirely. They’re technical grades that describe how accurately a diamond’s angles and proportions were executed.
Here’s the simple version:
Excellent/Ideal
Light performance is at its peak. The diamond is cut so well it looks lively from every angle. If your budget allows for this grade, go for it—nothing beats watching one of these under natural morning light.
Very Good
Still beautiful, still sparkly. A Very Good cut might allow a bit more leeway in certain proportions, but most people wouldn’t notice the difference without a side-by-side comparison.
Good
The stone may lose some brightness or symmetry, but it’s far from dull. Great for someone prioritising carat weight above everything else.
Fair/Poor
These grades usually suffer from light leakage—meaning the diamond simply doesn’t hit its sparkling potential. I rarely recommend them unless someone is designing something inherently rustic or intentionally muted.
Why Lab Diamond Cuts Are Evolving Faster Than Natural Ones
One of the things I genuinely love about working with lab-grown stones is the pace of innovation. Natural diamonds have been cut roughly the same way for decades because cutters must work around unpredictable inclusions, odd crystal shapes or tension-causing growth lines.
Lab-grown diamonds? They’re a bit like having a consistent canvas. That consistency has encouraged cutters to refine proportions, experiment with facet architecture and push boundaries on symmetry. I’ve seen new fancy shapes emerge in the lab-grown market long before they made it to natural stones, simply because manufacturers can test ideas without risking millions.
It’s a thrilling time in the diamond world—quietly revolutionary, even.
Choosing the Right Cut for Your Style (and Lifestyle)
I’ve noticed customers often get stuck deciding between size and sparkle. Here’s an easy way to frame it:
- If you want maximum brilliance, choose shapes like round, oval or cushion with an Excellent cut.
- If you want an elegant, understated glow, look for emerald or Asscher cuts.
- If you want the largest-looking stone, marquise and oval shapes give the most visual spread.
- If you want something personal or expressive, consider pear, heart or custom fancy shapes.
Lifestyle also matters. I once crafted a stunning marquise ring for a surfer who returned two months later with a chipped tip. (She was lovely about it, but my heart still winces remembering it.) If you’re active or work with your hands, consider shapes with protected corners—round, oval, radiant or cushion.
How to Spot a Well-Cut Lab Diamond Without Needing a Jeweller’s Loupe
Of course, I’ll always encourage people to view diamonds in person when possible. But here are a few at-home checks anyone can do:
1. Look for Even Sparkle Across the Stone
Patchy dark areas (we call them “extinction zones”) usually signal poor cut symmetry.
2. Tilt the Diamond Slowly in the Light
A well-cut stone keeps its brightness even as you rotate it. If it goes dark for a second, that’s light leakage.
3. Check the Table Reflection
In a round brilliant, you shouldn’t see a giant black circle reflected inside. That effect—nicknamed the “nailhead”—happens when the pavilion is cut too deep.
4. Don’t Get Hung Up on Carat
A slightly smaller but perfectly-cut diamond will always look more impressive than a heavy stone with poor proportions.
The Ethical & Aesthetic Harmony of Lab-Created Stones
People often start researching lab-grown diamonds for ethical reasons—less mining, less land disturbance, and a transparent origin story. But they often choose them because of beauty and value.
Cutting a lab diamond isn’t easier, but it’s more predictable, which lets cutters chase perfection. I’ve noticed customers gravitate toward lab-grown stones not just because they appreciate the sustainability angle, but because they love having access to cleaner, more precise cuts within their budget.
There’s something refreshing about that freedom.
The Future of Lab Diamond Cuts
If you ask me what’s coming next, I’d say smarter sparkle. Cutters are experimenting with new facet patterns designed specifically for the optics of lab-grown crystals. I’ve seen prototypes of hybrid cuts that combine brilliant and step facets in ways that simply wouldn’t be structurally stable in many natural stones.
We’re entering a stage where artistry can genuinely guide the craft—not just geology.
And honestly? I think that’s wonderful. Anything that pushes jewellery closer to true personal expression is worth celebrating.
A Final Thought
Choosing a diamond—lab-grown or mined—should feel exciting, not overwhelming. Cuts can seem a bit technical at first, but once you understand the basics, you start seeing stones differently. You begin noticing the way light moves, the way proportions shape personality, the way a diamond can almost “speak” when its facets catch the sun.
If there’s one takeaway from all my years at the bench, it’s this: trust your eyes. Trust your instincts. A diamond doesn’t need to be perfect—just perfectly right for you.
Whether you’re drawn to the fire of a round brilliant or the serene glow of an emerald cut, your stone should feel like it belongs in your story. And with the craftsmanship behind modern lab diamond cuts, you’ve got more beautiful options than ever before.