Summary in a few lines:

The world of diamond grading & certifications is dominant by GIA and AGS, being the top leaders in grading diamonds for decades, and they have both built a huge reputation which can’t be replaced easily.

There are many low quality labs that you should never trust, like EGL and HDR, but some labs have proven they can participate in this industry, not to GIA & AGS levels of course, but somewhere in between.

IGI is one of those, they have evolved in their grading technologies over the year trying to put their foot between the giants.

Here are two identical diamonds in terms of cut, clarity, color, and carat, the only difference is grading lab, this one by IGI, and the other one by GIA.

Being easiest thing to detect, do you think both diamonds share the same color grade? We doubt.

Should you buy an IGI diamond? If it’s a natural diamond, why you would want to do so when you can get GIA or AGS graded diamonds?

Lab-created diamond? IGI is doing a great job there, and James Allen is offering tens of thousands of lab-created diamonds that are graded by IGI.

Let’s get into details.

Diamond Grading & Certification

GIA is probably connected to “diamond certification” in your head! Just like how Google is the only search engine we think is there (or we pretend to think so).

The same goes for the Diamond certification industry, it is not exclusive to GIA or AGS. Yes they are the most reputable & known labs, but there are tons of certification labs out there that are less popular.

We surely know lots of these labs are probably way behind the competition, however, some actually are decent and follow protocols and scientific methods in assessing/grading diamonds, and IGI lab (International Gemological Institute) being one of them.

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What Stores Sell IGI Certified Diamonds?

If you’re getting your diamond from the Blue Nile, most probably, you’ll not be seeing any mention of IGI, but if you’re shopping at James Allen, you will notice that they are introducing more collections of IGI diamonds that you can check here (currently, James Allen has more than 7,000 IGI certified natural diamonds).

While not many other online stores showcase and sell diamonds certified by IGI, we truly believe that since James Allen (being the largest online diamond store with +500000 diamonds) is trusting IGI to list their diamonds, it’s worth at least a review, and then a fair and thorough comparison to the reputable GIA.

One of the most essential points to consider when you’re about to buy a gem is what type of certificate comes with that diamond, or to be precise: which certification lab has assessed the diamond and graded it accordingly?

You’ll notice that we are focusing a bit too much on the “diamond certificate” and advising that you do too; even more than ANY other factor.

Even more than the cut (although it stands on top of 4Cs order of importance).

Why is that?

Simply because if a lower quality lab (like EGL) grades a diamond with an H color as we recommend, while it’s an I or J for GIA, then you’ve purchased the wrong diamond, regardless of anything you’ve been recommended to get!

In this blog post, we’ll be going over IGI with it being a kind of controversial lab, it’s for sure has a good reputation these days, but why the giant Blue Nile (and others as well) didn’t take any steps toward listing diamonds graded by IGI?

Stay tuned…

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IGI Overview & Reputation

IGI (stands for International Gemological Institute) was established back in 1975 in Antwerp (Belgium), the labs were first founded as diamonds, colored gems, and jewelry certification institute.

Antwerp is historically known as the “home of diamonds” and IGI is considered to be the oldest certification lab there. They offer grading services for almost all types of diamonds & jewelry, including natural diamonds, lab-grown, Hearts & Arrows, colored…etc.

As for IGI reputation and if their certification process is reputable, it’s well-known that IGI operates on pre-set and documented standards and methodologies in the process of assessing and grading diamonds.

And just like “McDonald’s franchise”, these standards are applied across all their offices internationally, or maybe we should say “probably”?

Because it happened, and people on sites like Rapaport & RapNet communities have put this into test, they sent same diamonds to different IGI labs, and unfortunately results weren’t identical.

IGI New LogoIGI Offices:

The exponential growth in IGI presence is undeniable. Although they have started with one office in Antwerp, they now have +20 offices from LA to Hong Kong.

IGI employs +1000 gemologists in their offices.

IGI brands itself as the “largest international” labs, as they are located in many countries. However, this needs more explanation, since we saw in our GIA review that they have offices in 13 countries and almost 3,000 gemologists in their offices, so we’re not quite sure what they mean by the largest here.

Update: It looks like IGI has slightly changed their website headline from the “Largest organization of its kind” to the “World’s largest Independent Gemstone Grading Laboratory”, which kind of elaborates on their previous headline.

IGI Schools of Gemology

The interesting thing about IGI is that it has a School of Gemology, with 14 branches in Antwerp, Mumbai, Delhi, Hyderabad, Surat, Dubai, Shanghai, Ahmedabad, Chennai, Rome, Cavalese, Ascoli Piceno, Trecastagni, and Marcianise, where they offer diamond training and certification skills.

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In addition, their website mentions that they graduate thousands of jewelry professionals every year.

GIA vs IGI: Diamonds Grading Review & Comparison

All what we saw above come down to the million dollars question: 

Are they good as GIA or AGS?

Put simply, we can’t say that IGI is good as GIA or AGS, but at the same time, we neither can’t say they are bad like EGL, these labs come somewhere in between.

We saw that IGI has straight-forward guidelines to grade & assess diamonds, but they might not be as strict as the big names (GIA & AGS); the “sharks” in the diamond industry.

This is due to many reasons, mainly being the inspection tools they have and the expertise of local gemologists they work with.

GIA vs IGI Grading Strictness Comparison

Following our thorough assessment and deep comparison of diamonds graded by GIA & IGI, we’ve noticed a slight upshift in grading some stones’ characteristics, mainly in diamond clarity and color.

To clarify, a diamond that has been graded as VVS2 by GIA might be graded as VVS1 by IGI.

Likewise, an F color diamond (by GIA) can be seen as E grade by IGI.

This can go a bit extreme and differences might be in 2 grades, like I1 in GIA being SI2 with IGI.

But to put this in context, it’s not the case always, but it happens more often than not.

We’ve seen in our EGL Labs review that their diamonds should not be an option for any buyer, they are very known to inflate color and clarity levels with two or even 3 grades.

Some would say: Okay, IGI doesn’t have that issue though, its inflation is by one grade at most, and probably will be reflected in price, so this doesn’t sound “a big deal”!

Well, we wouldn’t say that it’s “not” a big deal, nor it is! It all comes down to the specific diamond itself and your intention behind getting it (are you willing to resell anytime for example?) Will you be insuring it for instance?

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Generally speaking, getting a diamond with grades that are higher than its actual grades (even as little as one grade difference) is not recommended.


  1. You are paying an extra amount of money for a higher grade that doesn’t actually exist. However, this is not the case all the time, IGI diamonds are cheaper than GIA, because “they know” that they are not as reliable as GIA, so you won’t be paying more money at all times.
  2. Reputation matters: When you want to sell the diamond, it won’t be easy to convince a seller with a diamond certified by any lab other than GIA or AGS!
  3. Even if you were able to sell it, you will also lose more money.
  4. In general, most diamond insurance companies cover diamonds that are certified by either GIA or AGS.

If you found two diamonds graded the same color & clarity (one by GIA & another by IGI) for the same price or even close, it would be wise to pick the GIA diamond as the IGI in this case might be a bit overpriced in this case.

Also Read: Diamond Certification: How to Read a Diamond Grading Report?

Despite the fact that some of the largest online stores display and sell IGI-certified diamonds (one of them is James Allen as you can see here), we can’t say for certain that IGI is a GO or a NO GO for that matter! 

Although IGI is a good-reputable certification lab and follows well-structured guidelines to assess diamonds, this depends on many other factors. We’ve already seen stones certified by IGI that are reasonably priced, whereas others were highly-priced as if they were a GIA-graded diamond with the same specifications.

You have to be careful in picking the right diamond If and only if the price makes sense.

Profitability vs Non-profit Labs

IGI is a company (for-profit), and it was kind of a family business (owned by the Lorie family) for almost all its lifetime, until recently in late 2018, when the Chinese conglomerate Fosun (Shanghai-based company) acquired 80% of IGI.

Some resources mention that the deal was close to €100 million! Just to give you an idea about how large is this business.

On the other side, GIA is a non-profit organization, in other words, no one is getting rich by grading diamonds, period.

IGI Grading & Reporting Services Review

As a specialized organization in gemstones and diamond grading, IGI offers many reports showing different characteristics of diamonds or other jewelry pieces. We’ll be taking a look at some of the most popular reports provided by IGI:

1- Loose Diamonds Report:

Similar to other diamond certifications in the industry (GIA, AGS, or others), this report assesses the diamond characteristics, and assigns grades based on their standards, this report lists diamonds 4Cs, what Shape the diamond has, Polish, Symmetry (with its details like measurements, table & depth, etc.), as well as fluorescence.

Also Read: Is Diamond Fluorescence Good or Bad?

It also includes a graphic representation of the diamond itself which shows inclusions found in different locations on the diamond. Here is a sample for a diamond report by IGI:

IGI Sample Diamond Report

2- Hearts & Arrows Diamonds Report

This diamond type is becoming more and more popular now, especially with the big online retailers who have introduced new lines of products and branded them as unique & spectacular diamonds with unmatched cut grade.

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We’ve seen this in James Allen’s collection: True Hearts™, whereas their biggest competitor (Blue Nile) named their similar collection Astor™, and recently, the premium quality store Whiteflash penetrated the market with their A CUT ABOVE® unique collection.

Due to this unprecedented growing demand for the “Hearts & Arrows” diamonds, and since GIA doesn’t include any specific details about these branded collections in their certificates, a huge opportunity presented itself for labs like IGI to issue grading reports for diamonds with Hearts & Arrows (premium cut).

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IGI uses the “Hearts & Arrows” gem scope to check if ALL diamond facets are aligned to appear correctly, which means full symmetrical proportion to the diamond.

The report is almost identical to the previous report with one slight difference being that this report includes a comments section to confirm that this diamond is a “Hearts & Arrows” one, similar to the one below:

IGI Sample Hearts & Arrows Report

3- Colored Diamonds Report

IGI also offers a service to grade and provide a detailed assessment of colored diamonds, since colored diamonds are examined and assessed on a different basis than the colorless diamonds (colorless here refers to diamonds in D-M range, not necessarily completely colorless like D color) we’re familiar with.

Why is this report important to be a separate one?

This is because a lot of “fake” colored diamonds are actually colorless with low color grades, but they have been treated to alter the diamond’s color!

The Colored Diamond Report by IGI gives many details about the diamond color; its origin (natural or treated), grade, distribution, and a comment section, similar to this one:

IGI Colored Diamond Report

4- Synthetic / Lab-Created Diamonds Report

And here, IGI shines and dominates the grading industry.

Search for lab-created diamond on James Allen, Clean Origin, Brilliant Earth, or any other major lab-grown diamonds store, more than 90% of their inventory is graded by IGI.

People are constantly looking for cheaper options for almost everything out there, and diamonds are no exception! Lab-created diamonds have been more adapted in the past few years due to financial matters, as well as staying safe from conflict diamonds.

But is it easy to identify a lab-created diamond though? If it’s, then why would people consider even going for it?

The truth is: It’s IMPOSSIBLE to spot the difference with the naked eye. No one can detect the difference between a natural diamond vs. a synthetic one by just looking at it.

Regarding the IGI report for the lab-grown diamond, it’s identical to the natural diamond report, except it has a line that clearly states that this diamond is “Laboratory Grown”, and the report name of course.

We encourage you to read our article that covers All you Need to Know about Buying a Lab Grown Diamond if you’re thinking of getting one.

5- Other Reports by IGI

The above reports are the most popular reports that IGI provides, and as a matter of fact, they’re also what people are looking for. However, IGI has other reports as well like Jewelry Report & Colored Stone Report

We will not be getting into details about these but will refer you directly to their respective pages on IGI here & here.

Summary: GIA vs IGI Grading Standards, Should You Get an IGI Diamond?

After all that has been discussed above, and although James Allen does sell IGI-certified diamonds, we wouldn’t always suggest to go with an IGI-certified diamond. For example, after it has been inspected and matched with similar diamonds from GIA or AGS, are they the same price? Or will you be getting a better deal on it?

Another important point to keep in mind is to check if the diamonds are high grade on color and clarity. In many cases, we’ve seen the inflation of grades in IGI happen on lower clarity (SI2 & SI1) & color (I & J) grades.

Our top recommendation on diamonds is to always get a GIA or AGS diamond (with GIA being the first go to option because it’s simply the best certification lab out there).


Still not sure where to buy your diamond?

We always recommend shopping diamonds online and created a Full guide to shop diamonds like a Pro.

Among online retailers, here are our favorite stores (click their logo to visit store):

1) James Allen: Our favorite online store, best diamond imaging technology available today, comes with the largest collection with more than half a million loose diamonds.

Latest JA Logo2) Blue Nile: Widest collection of loose diamonds of all sizes, great imaging technology for most of their  inventory (hundreds of thousands of diamonds), great customer support.

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3) Whiteflash: Home Of A CUT ABOVE® Super Ideal Diamonds, they stand out from the crowd by offering premium diamonds cuts, tailored to those who love the details, at great prices too.

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About the Author

Christopher Morgan

Christopher Morgan is a talented wordsmith with a passion for diamonds and a flair for storytelling. With a unique perspective on the industry, Christopher brings a fresh voice and captivating narratives to his writing.

Having been captivated by the brilliance of diamonds from an early age, Christopher immersed himself in the world of gemstones. His extensive research and experience have given him a deep understanding of the diamond industry, from mining and cutting to the cultural significance of these precious gems.

Christopher's engaging writing style and ability to blend technical knowledge with artistic expression make his articles a delight to read. Through his work, he aims to inspire readers and ignite their curiosity about the fascinating world of diamonds.