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IGI vs GIA Diamond Certification

by Julianna Church
Last updated on September 19, 2023

If you buy a loose diamond online, it likely comes with a physical or digital document called a diamond certificate. Ten years ago, most people that walked into a jewelry store had no idea about diamond certification because chain retailers used to carry very few in store. If you were budget-conscious, they knew they couldn’t sell you one of their overpriced engagement rings with IGI or GIA certificates. So, they’d downplay the importance of buying certified diamonds. Keep reading to learn the differences between IGI vs. GIA diamond certification!

Diamond Grading Reports and Diamond Certification

color grading scale

Diamond reports are like the birth certificates of diamonds. Each one is evidence that a gemological laboratory has analyzed the quality factors of your diamond, including:

  • Cut grade
  • Clarity grade
  • Color grade
  • Carat weight
  • Diamond shape
  • Proportions
  • Symmetry
  • Polish
  • Length to width ratio
  • Fluorescence
  • Clarity plot (usually)
  • Laser inscription on girdle (some labs do this on request)
  • Origin

The exact elements of your diamond grading report will depend on which gemological laboratories created the report. Having certified diamonds doesn’t necessarily guarantee your diamond’s grades or quality because different labs grade diamonds differently.

Some diamond grading reports aren’t from laboratories that are reputable in the diamond industry. At Clean Origin, we offer our customers diamonds with GIA diamond grading reports, IGI grading reports, and GCAL grading reports.

Today, we’re going to compare the diamond certification processes between two of the biggest diamond laboratories: IGI and GIA.

GIA Certified Diamonds

loose diamonds on the palm of a hand

The Gemological institute of America is the world’s foremost authority on diamonds and other minerals. They implemented the 4Cs of Diamond Quality: color, cut, clarity, and carat weight. This effectively set the standard for diamond quality.

The GIA has many different locations, with its main hub in Carlsbad, California. Some of the major ones are the following:

  • New York
  • Mumbai
  • Bangkok
  • London
  • Tokyo
  • Hong Kong

Aside from these larger laboratories, the GIA also has various smaller offices around the world.

Here are some positives when you buy GIA certified diamonds:


  • Most reliable diamond certificates– The GIA is the leader in diamond grading and gemology. You can be sure your diamond grades are accurate with GIA certified diamonds.
  • Consistent grading– It’s important to grade diamonds according to strict guidelines and to do so with consistency and accuracy. All diamonds should be graded according to the same standard.
  • Retains value– GIA diamond certification allows the value of natural diamonds to increase. Laboratory diamonds with GIA certification may not be eligible for upgrades or sale in the resale market, but secondhand buyers are more likely to buy GIA certified diamonds over another lesser-known laboratory.


  • More expensive– A diamond accompanied by a GIA diamond certificate is usually more expensive than diamonds with non-GIA reports. When you’re the gold standard in the diamond industry, you can charge a little more for your certificate. But not everyone may be able to afford that. Be aware that you’re likely to pay much more for a GIA diamond grading report when buying certified diamonds from major jewelry chains. Make sure to compare prices with online diamonds before making your final purchase.
  • Stricter when grading diamonds– With great power comes great responsibility. GIA diamonds are graded with the strictest standards. Typically, this is a good thing. On the other hand, there are many diamonds that straddle the lines between diamond grades. For example, the GIA may grade your diamond as SI1 clarity, but another reputable lab may give your diamond a VS2 clarity grade (check out this diamond clarity chart for more info about clarity). Sometimes, having GIA certification means your diamond may be undervalued compared to what it could have been if you had gotten it graded by another lab.

IGI Certified Diamonds

loose diamonds on a white piece of cloth

The International Gemological Institute is another reputable laboratory for diamond reports. The IGI was founded in 1975 by Marcel Tolkowsky at IGI Antwerp. Today, there are different branches of the International Gemological Institute in the following cities:

  • New York
  • Hong Kong
  • Mumbai
  • Bangkok
  • Dubai

You may obtain an IGI certificate for natural and lab grown diamonds, colored gemstones, and mounted jewelry, such as a diamond that’s mounted to an engagement ring setting. You can also send in your own diamond to get an IGI certificate if your diamond is uncertified.

Here are some positives when you buy IGI certified diamonds:


  • IGI diamond certification is usually less expensive than GIA certified diamonds of the same quality.
  • IGI certification is typically recommended when obtaining lab diamond grading reports. Lab diamond GIA certificates were revamped in 2020 to match the quality of an IGI report, but unfortunately, most retailers will only carry a GIA natural diamond report, not GIA certificates for lab grown diamonds. At Clean Origin, though, we carry both GIA and IGI reports for lab created diamonds.
  • When obtaining your own IGI report for an uncertified diamond, the International Gemological Institute is known for its speedy and quick turnaround for IGI certificates.


  • IGI certification has lost some of its reputation, as the International Gemological Institute has become the choice laboratory for popular chain jewelry stores. Many stores are selling diamonds with IGI graded diamonds because of how much cheaper and quicker it is than GIA diamond certification.
  • If you’re hoping to invest in natural diamonds for the best value, it’s not recommended to purchase IGI certification over GIA certification. Some places will only take diamonds with GIA certification or American Gem Society (AGS) certification when re-selling a natural diamond. However, Clean Origin only offers lab grown diamonds. There’s been no issue or dispute regarding quality of accuracy of lab grown diamonds with an IGI report.

Why Certified Diamonds Are Important

bride wearing multiple diamond rings

So now that you have an idea of the differences regarding IGI vs GIA diamond grading and reports, you might be wondering how important this all is, anyway. I mean, why would you need a report if you already know the diamond’s grades?

It’s no secret that customers are getting fed up with the sales practices and prices from brick and mortar chain retailers. That’s what brought them to buying online diamonds. But as chain retailers have slowly bought out different online diamond stores, too, customers are searching for independent jewelers outside the corporate umbrella.

There’s plenty to go around with marketplace sites and sellers. But when you don’t buy from a regulated company, you honestly have no idea where that diamond comes from unless it has a grading report from a reliable lab.

Protects You From Being Scammed

A diamond certificate is your evidence that you aren’t being ripped off. Someone could sell you a diamond off Etsy rated with VS2 clarity and an Excellent cut in the description. If you went to get the diamond certified and discovered that it has a Very Good cut and SI2 clarity, you would probably be very mad because that’s a whole different price.

Not All Certifications Are Legit

But remember, not just any diamond certificate will do. Different labs have different standards for grading diamonds. Just because a listing has a diamond certificate doesn’t mean you shouldn’t research the grading lab beforehand. Not all certified diamonds are legitimate.

Unfortunately, GIA and IGI reports are able to be faked as well. There’s been talk on different jewelry communities about how sellers can design GIA diamond dossiers and other reports. They can even match other diamond report numbers so it looks legitimate when you try to match the report number on the GIA site.

Now, doesn’t all that sound like a major headache?

Fortunately, there’s a solution.

Buy from a trusted retailer that not only carries legitimate diamond grading reports, but also hasn’t succumbed to the corporate umbrella. Like us.

Navigating diamonds online can be a grueling process, especially without knowing the different diamond companies that pop up. But with over 100 years of combined diamond knowledge, we are quite familiar with diamonds and know exactly how to help you find the right diamond certification to fit your needs.

Should You Choose a GIA Certified Diamond or an IGI Certified Diamond?

woman wearing three diamond rings

Ah, yes, the final question, dear reader. An IGI vs GIA diamond certification?

On the one hand, a diamond with a GIA report is the gold standard of the diamond trade. If you want the best in the industry, a GIA report is the way to go. Unlike IGI diamonds, GIA grading reports come with a premium cost.

IGI diamonds might be more appealing to someone who really doesn’t want to spend a ton on their engagement ring. After all, there’s no rule saying that you have to in order to prove your love. Many couples opt to spend more on their honeymoon or first home instead of their wedding jewelry.

Whatever the case may be, an IGI diamond report tends to come at a lower price than a GIA report. The grades of the diamonds could all be the same, but the cost is usually still lower.

Some may argue about the accuracy and consistency of how the IGI is assessing diamonds, but there have been no discrepancies between IGI reports for lab grown diamonds.

At the end of the day, choosing an IGI vs GIA diamond certificate is up to the buyer. For those who are concerned about value and top tier diamonds, go for a GIA certificate. But if you don’t necessarily feel like you need that, IGI reports are a great option, too.

But whatever you do, make sure you purchase loose diamonds with legitimate diamond reports from a legitimate diamond company. Like us.