Lab-grown diamonds have taken the jewelry industry by storm—and for good reason. Imagine this: a few decades ago, owning a two-carat diamond meant spending tens of thousands of dollars and perhaps a nervous glance from your bank manager. Today, lab-grown diamonds make that dream a reality at a fraction of the cost. Pretty amazing, right?

But there’s another side to this dazzling story. I recall visiting Antwerp, Belgium, the legendary diamond district just a few years ago. Diamond traders were shaking their heads, lamenting the steep decline in natural diamond prices. One dealer joked bitterly that his son’s PlayStation would soon cost more than his inventory. It’s clear that lab-grown diamonds have significantly impacted market values.

Quick Summary: What I think about Lab-Grown Diamonds

Don’t get me wrong; I think lab-grown diamonds are great. They offer the same sparkle, hardness, and chemical composition as mined diamonds. Environmentally conscious consumers especially appreciate their lower ecological footprint. And it’s truly fantastic seeing young couples proudly sporting impressive stones without breaking the bank.

Still, a part of me misses the exclusivity and the romance tied to natural diamonds. The lore, the rarity, and yes, even the slightly painful price tag made them feel special and irreplaceable. Lab diamonds democratize luxury, and while that’s a beautiful concept, it inevitably alters the very nature of what we consider luxurious.

Here’s a real-life example: a close friend recently proposed with a three-carat lab-grown diamond. It was genuinely stunning. Five years ago, such a stone would have been impossible on his budget. But today, everyone around us admired its sparkle without batting an eye at its size. That’s both wonderful and a bit surreal.

In the end, I suppose it’s about balance. Lab-grown diamonds are here to stay, and they bring undeniable value and beauty to many lives. Yet, the industry’s traditionalists, myself included, can’t help but feel nostalgic about an era when diamonds felt more like rare treasures and less like perfectly crafted commodities. Perhaps, though, this is simply the future we need to embrace.

My Experiences so far in the industry

Maybe I haven’t introduced myself properly though. Let’s start from the beginning. I’m a diamond grader at the International Gemological Institute (IGI), and I specialize in the shiniest newcomers to the gem world – lab-grown diamonds. Every day I slip on my lab coat (bedazzled with a few sparkly stickers, of course) and step into a world of glittering gems and high-tech instruments. IGI is no small operation; in fact, we’re the world’s largest independent gemological lab, with 20 laboratories worldwide issuing millions of grading reports each year​. IGI was also the first gem lab to get ISO accredited for grading both natural and lab-grown diamonds​, which is a fancy way of saying we meet rigorous international standards for accuracy. We don’t mine or sell diamonds – we just grade them – so you know our evaluations are unbiased.

Being at the forefront of gemology means IGI was ahead of the curve on lab-grown gems. We actually foresaw the rise of lab-grown diamonds as far back as 2008 and were the first global lab to start certifying them​. Today, IGI handles tons of lab-grown stones (literally; we even screen millions of carats of tiny diamonds for big jewelry brands to ensure no imposters get mixed in​). So if you’ve got a lab-grown sparkler, there’s a good chance an IGI gemologist like me has peered at it through a microscope.

Now, let me take you through my day and the fascinating (and sometimes quirky) process of grading these lab-created beauties. From the technical nitty-gritty of the “4 Cs” to the detective work of confirming a diamond’s lab-grown origin, and even the office shenanigans over coffee, you’ll get an inside look at how we balance science, precision, and a bit of humor in our daily routine at IGI.

Grading Lab-Grown Diamonds: The 4 Cs

At the heart of my job is evaluating the famous “4 Cs” of each diamond: Color, Clarity, Cut, and Carat Weight. Lab-grown diamonds are chemically and physically the same as mined diamonds, so we grade them by the same international standards for quality​. Still, each stone has its own personality, and getting to know it through the 4 Cs is like interviewing a very sparkly job applicant. Here’s how I break it down.

Color

Color grading is all about what you don’t see. The ideal diamond is colorless, which we designate as grade “D” on the alphabetical scale that runs all the way to “Z” (which would be a visibly yellowish or brown tint)​. I grade color by comparing the diamond against a set of master stones under standardized lighting. Picture me in a quiet light booth, holding the diamond upside-down and peering at its icy-white or perhaps slightly warm hue. Lab-grown diamonds can be just as colorless as natural ones, though sometimes the growth process leaves a slight tint. For instance, if certain elements sneak into the growing chamber, a lab-grown diamond might exhibit a hint of yellow or even blue. The environment and seed crystal used in its creation can affect its color outcomes. In practice, I’ll line up the gem against our master comparison stones, squint like a discerning art critic, and decide if it’s a pristine “F” or maybe a sunny “J”. It’s meticulous work, and yes, we graders can debate whether something is a G or H color for far longer than one might think reasonable (with good humor, of course).

Despite the serious focus, there’s room for a chuckle. One time, a colleague joked that grading a batch of near-colorless lab diamonds felt like sorting a stack of blank papers – you start questioning if D, E, and F even look different. (They do, trust me, but only if you’re as obsessively trained as we are!). On another day, I graded a rare fancy color lab-grown diamond (a vivid yell0w) which was a nice break from the sea of colorless stones. It was very recent that IGI got the technology to grade lab-grown fancy color diamonds. Fancy colors get a different grading scale and special descriptors, allowing me to break out creative color terms like “Fancy Vivid” vs “Fancy Light.” It’s moments like those that add a splash of excitement (and literal color) to the routine.

Clarity

Next up is clarity, essentially the internal “complexion” of the diamond. I use a 10× binocular microscope (and a trusty loupe for quick looks) to examine any tiny birthmarks inside the diamond​. We’re talking about inclusions – little imperfections like specks of minerals, tiny cracks, or clouds. In natural diamonds, inclusions might be bits of other minerals or internal stress marks from eons in the earth. In lab-grown diamonds, we also encounter inclusions, but they have their own flavor. For example, an HPHT-grown diamond (one created by High Pressure High Temperature method) might contain tiny metallic flakes from the growth catalyst – I’ve affectionately nicknamed these “lab glitter.” Meanwhile, CVD-grown diamonds (grown by Chemical Vapor Deposition) can show subtle growth patterns, like faint wispy lines, when viewed under magnification.

Don’t get me wrong: lab-grown diamonds can be just as flawless as Mother Nature’s finest. In fact, many lab-grown stones I see are remarkably clean, sometimes graded VS or even VVS (Very Very Slightly included) or higher, meaning even under 10× magnification it’s hard to find anything wrong​. But when there are clarity characteristics, part of my job is to map them. I carefully note each inclusion’s size, type, and location, often sketching them on a diagram that will go into the report.

One quirky thing about clarity grading: it can feel like deciphering a diamond’s diary. Each inclusion is a story of how that crystal grew. I might find a microscopic metallic fleck and think, “Ah, you were in a rush growing in that HPHT press, weren’t you?” If a lab diamond is too flawless, that’s notable as well: a truly flawless (FL) diamond is rare, and when I find one, I practically do a happy dance (after double-checking with a colleague that I didn’t miss a tiny feather or speck, of course).

We graders also have a bit of insider humor: sometimes an inclusion’s shape will resemble something funny. Once I saw an internal inclusion shaped like a tiny gemstone (yes, a gem inside a gem!) and we joked that the diamond was trying to grow its own jewelry. Regardless of humor, clarity is a serious business. Whether a stone is Included (I) with obvious flaws or Internally Flawless (IF) with none, we document it meticulously. And yes, inclusions in lab-grown diamonds “appear much the same way” as in natural diamonds​, so it takes sharp eyes and sharp tools to grade them right.

Cut

If color and clarity are about a diamond’s nature, cut is all about nurture – how well a diamond has been shaped and polished from its original rough form. Cut is my personal favorite C, because it’s where the diamond’s sparkle is either made or lost. We evaluate cut quality by examining a bunch of factors: proportions (like the angles and lengths of facets), symmetry (how well those facets align), and polish (how smooth the surfaces are)​. An excellent cut can make even a slightly tinted or included diamond look breathtaking, while a poor cut can make a perfect diamond look dull. So, no pressure on us graders… we just have to judge the work of master diamond cutters around the world!

Practically speaking, I measure angles and facet proportions using specialized scopes and sometimes computerized devices. For example, I check the table percentage (the size of the top facet relative to the width) and the depth percentage, which are key indicators of how light will travel in the stone. IGI reports list these measurements in detail – we’re talking crown angle, pavilion angle, girdle thickness, culet size, you name it​. As a grader, I take all those numbers and observations and assign an overall cut grade, typically on a scale from Excellent down to Poor​. Most lab-grown diamonds I see are cut to pretty high standards (since growers and cutters know their customers want maximum sparkle). Still, I occasionally encounter a wonky cut – maybe the stone was cut to save weight rather than optimize beauty, resulting in a too-thick girdle or an off-center table. When that happens, I might let out a dramatic sigh in the lab, and my coworkers know I’ve found a “character-building” diamond (our code for a stone that teaches us patience!).

On the lighter side, we sometimes play “guess the cut grade” before we formally measure. A colleague might slide a diamond over and say, “Think this one’s a Very Good or Excellent cut?”, a bit of friendly competition. The person who guesses right gets bragging rights and maybe a free coffee. It keeps us on our toes. After all, when you stare at gemstones all day, a little game now and then livens things up. And nothing beats the satisfaction of examining a lab-grown diamond that’s cut just right –those facets twinkle like they’ve got their own spotlight. In those cases, writing “Excellent” on the report’s cut grade line comes with a smile.

Carat Weight

Finally, the easiest of the 4 Cs to explain (but still crucial): carat weight. A carat is simply a unit of weight for gemstones, equal to 0.20 grams (about the weight of a paperclip)​. We determine this by carefully weighing the diamond on an electronic micro-balance scale. And by carefully, I mean carefully these scales are super sensitive. I often joke that I hold my breath while weighing a diamond so as not to confuse the scale with a stray breeze! If you ever visit a gem lab, you might witness a comical scene of gemologists hovering like statues around a scale. In reality, we do shield the scale from air currents and make sure it’s calibrated daily.

Most lab-grown diamonds come in popular sizes like 0.50 carat, 1.00 carat, etc., but we see all sorts of weights. Sometimes I’ll weigh a stone and get something like 0.99 carats. The difference between 0.99 and 1.00 might seem tiny, but trust me, some clients care a lot – hitting that magic “1.00” number can be a psychological win (even if your eye can’t tell the difference). We report carat weight to two decimal places on the certificate, so precision is key. One time, a new trainee accidentally recorded a 1.00 carat stone as 1.000 (three decimals) and quipped that they were giving the customer a bonus 0.001 carat for free. We had a good laugh and then gently corrected the format.

There’s not as much humor to squeeze out of weighing diamonds, but one running gag in the office is weighing other objects on our diamond scale (when the boss isn’t looking). I once caught a coworker trying to weigh a chocolate chip from a cookie – strictly in the name of science, of course. (For the record, it was about 0.02 carats… a lightweight chip!) In all seriousness, accuracy in carat weight is essential because it, combined with the other Cs, determines a diamond’s value. Lab-grown diamonds typically cost less than their mined counterparts of the same size, meaning consumers can get a bit more bling for their buck​. As a grader, that doesn’t change my job – a 1.50 carat lab-grown gets the same scrupulous measurement as a 1.50 carat natural. But it’s nice knowing these lab-grown gems make certain dream rings more affordable.