There are a lot of things you have to check & verify before getting a diamond, and maybe one of the most important one is the diamond grading / certification lab.

Why? Because simply this lab will grade ALL other things that you will make your purchase decisions based on them, whether it’s a color, clarity, fluorescence, you name it, all this need to be graded by a reputable lab,

And when people purchase diamonds, they expect the highest quality from the merchant and the one way to confirm that is through a diamond dossier or what is popularly known as a diamond certification.

That’s why when you visit sites like James Allen & Blue Nile, you will see that all their diamonds collection are certified by the most reputable certification labs like GIA & AGS.

What is Diamond Certification?

Diamond certification (also known as a diamond grading report) provides written proof of a diamond’s attributes and an index of the diamond’s fair market value. Diamond certification also allows you to make an intelligent comparison with other diamonds, either in the same jewelry store or in another.

A diamond certificate includes the 4Cs:

  • Diamond Color – A sliding scale starting from D (colorless diamond) to Z (noticeable yellow).
  • Diamond Cut –  A diamond’s cut grade reflects the perceived sparkle of the stone (don’t confuse cut with diamond shape).
  • Diamond Clarity – A sliding scale from FL (Flawless) to I3 (Included) that reflects the severity the tiny imperfections present in many diamonds.
  • Diamond Carat – Carat is a term that refers to the weight of a diamond.

It also describes characteristics of diamonds such as the diamond’s shape, measurements, symmetry and any imperfections, whether internal or external.

Feel free to read our full post about diamond certification to know more about the details.

What is the GIA Diamond Certification Lab?

GIA LogoOne of the most (actually, it is the most) widely recognized and respected diamond laboratories is the GIA (Gemological Institute of America).

A Quick Look at GIA History

Dating as far back as 1931, the GIA was formed as an independent non-profit organization to provide guidance, standard, research and education to purchasers and the entire gemstone industry.

In the past, buyers had to rely solely on the word of jewelry sellers which were often misleading, but with the advent of the GIA, consumers are now well-informed.

To put this into context, what GIA did back in the days has changed the whole diamonds industry, globally! Now when we search for any diamond, we don’t take any word by the jeweler for granted, if it’s not written on a grading report, it’s does not exist! Our current shopping behaviour is based on what GIA labs have accomplished over the past 90 years!

in 1953, GIA issued the first diamond grading reports; and those reports have become the international jewelry industry’s benchmark we see today.

With its immense caliber of trust globally, the GIA is favored amongst the world’s famous and reputable jewelers, a main reason behind that could be because GIA is a non-profit organization, which means that they aren’t on the seller (merchant side), and neither the buyer, they are naive in grading diamonds.

This is very important because when labs have some shareholders (a.k.a. they want more money), you will see more ways by these labs to the favor of the merchant, like EGL and how they created new terminologies like SI3 just for the sake of merchants!

4Cs of DiamondsGIA Labs & Locations Today

Today, more than 3000 employees work at GIA in its offices in 13 countries, and it’s the largest & most widely-adopted certificate for diamonds, this is easily understandable when we know that they set their inspection standards to very high levels.

GIA gained this huge credibility not only because they are very old in the diamond industry, but because they were the creators of the global standardization of any diamond: The 4Cs! Yes, GIA created (established) the 4Cs standards.

GIA is also known to be a leading provider for diamond education on the web, they create a lot of online courses about diamonds that anyone can enroll and become a GIA Alumni, they also have endless articles on Diamond Education.

This is a quick look on GIA, what is it, when they were founded, and how do they operate, now let’s take a look at their grading / certification system.

What is a GIA Certification?

When a jeweler or diamonds merchant (usually the big ones, like James Allen or Blue Nile) send a diamond to GIA labs to grade it, GIA will take the diamond to their labs and inspect, grade, and report the diamond on a certificate that you can see when shopping online on the mentioned stores, you may also see it in most reputable local jewelry stores.

The GIA certificate (also known as GIA grading report) contains a full scientific and unbiased information of your diamonds 4Cs (Carat weight, Color grade, Clarity Grade and Cut Grade, more on these below), and many other details.

These characteristics have been reported using high standards that GIA follow to grade diamonds based on known scales (at least for GIA), so for example, Clarity is graded based on GIA 11 clarity grades scale, while Color grading follows the letters scaling from D to Z.

Why GIA Color Grading Scale Starts with D not A?

Because color grading before GIA wasn’t following any standard, some grading scales were A, B, or C, others included Arabic numbers, third were using Roman numerals, so GIA wanted to skip all this, and start fresh with a letter that wasn’t used before, and it was the D.

Blue Nile Ring 2

This is an example of a real GIA certificate for this diamond on Blue Nile, and you can see, it has a lot more information than the mentioned 4Cs above, more on this shortly after the image:

GIA Certification

What Information is Listed on a GIA Report?

We’ve mentioned above some of the most important characteristics that are included in a GIA certificate report, but here is the full list:

1- Unique report number that you can use to look up the diamond online and make sure the report you have is original.

2- 4Cs: Carat, Color (a * next to the color grade means the diamond has been treated to alter its color with extra details underneath), Cut, and Clarity, more on these terms below.

3- Diamond profile to its proportions, which shows table & depth, facet, crown angle, and other dimensional factors.

4- Diamond shape. (Read: Diamond Cut vs. Diamond Shape & The Most Popular Shapes)

5- Measurements.

6- Polish.

7- Symmetry.

8- Fluorescence.

9- Clarity Characteristics: This section shows if the diamond has inclusions with details about them, note that this section is available only for diamonds that are 1 carat and above.

Which Diamond Certification is the Best? Is it GIA?

Diamond certification is not only done by GIA, you already know that there are tens of other certification labs, AGS, IGI, EGL (many of them), HRD, GCAL, GSI, and the list goes on.

Every lab has its own standards to grade diamonds, and one of the main things that makes lab A better than lab is Consistency!

You shouldn’t see two diamonds with “almost” same color, but you find out that they are 2 or 3 color grades apart!

Labs also should be consistent to other “reputable” labs scaling, so when GIA grades a diamond with I color, it doesn’t make sense for EGL to come and grade it as F! And this happens a lot with EGL actually.

Out of all the labs in this industry, a few only stand out with strict and consistent grading: GIA, AGS, and IGI is going all the way there as well.

But between all these 3, which lab is the best?

We would go for GIA as a first choice when you want to pick your diamond, followed by AGS right after that, and to be honest, AGS in terms of grading isn’t lower in quality than GIA, but it’s just of how this industry is controlled, GIA has higher demand & reputation, so if you ever wanted to resell your diamond, a GIA one will be easier to sell (and will get you a better price as well).

Why GIA is Considered the Best Diamond Certification Lab?

The significant benefits you stand to gain from a GIA certificate include but are not limited to:

1. They Created the 4Cs!

The GIA 4Cs grading gives various parameters in finding the right quality diamond for you:

1. Carat: One carat of diamond is equal to 0.2 grams which is about the same weight as a paper clip. Every carat is split to 100 points meaning 0.50 carats equals 50 pointers.

2. Clarity: Mined diamonds are created by nature under intense heat and pressure. Hence, the clarity is usually too tiny to be visible to anyone’s eyes other than that of a trained gemologist using magnification. The GIA Clarity scale has eleven grades ranging from flawless to included.


Read: What is VVS Clarity & Why it takes all that importance?

3. Color: Truly colorless diamonds are very rare and greatly valued. The color scale by GIA uses letters to indicate the absence of color, starting with D which represents colorless and ends with Z which represents light yellow or brown.

It is important to note that color distinctions are quite subtle and only usually visible to a trained eye, but the differences usually have an impact on pricing, don’t forget to check our Diamonds Color Chart with Real Diamonds Images.

Diamond Color Chart with Fancy Colors

4. Cut: The term “Cut” refers to how a diamond’s proportion and angles relate to light. Lots of factors affect a diamond’s cut grade, some of which are total face-up,  appearance, craftsmanship, and design. The GIA cut scale ranges from Excellent to Poor.

2- GIA provides you with all information when shopping for diamonds:

Add to the 4Cs, the report will include a lot more than that so you can know every detail of the diamond you’re getting.

The detailed nature of the report opens you up to find the options that fall in line with your budget. Whether you’re purchasing an engagement ring, family heirloom, bracelet or necklace, the GIA certificate clearly sets out the diamond attributes in a way that makes it easy to compare and choose.

James Allen Find the One3- Brings maximum value to your diamond when re-selling

A certified diamond means that it has been quality tested thoroughly in a gemological laboratory.

When your diamond is GIA certified, you get first preference when selling to a jeweler, so they will not be able to play around that certificate, when you say GIA, it’s a GIA!

4- It provides assurance and peace of mind

Whether you’re shopping online (on sites like JamesAllen) or visiting a walk-in store to purchase your diamond, A GIA certification will be backing your choice of diamond, and after a careful look at the document you are sure that you are purchasing quality and not getting ripped off.

When investing in a large diamond, the cost of getting it certified is insignificant when compared to the value of paying a huge amount of the money for something that has no worth.

Read: Comprehensive Review of James Allen

5- Prevents synthetic/lab-created diamonds

With the advancement in technology that allows synthetic diamonds to be produced to a high standard. It may be hard to place a difference between a genuine and synthetic diamond. The GIA certification acts as your guide and protection against such unauthentic purchase.

If a diamond is lab-created, its GIA report will include that, as we’ve covered in our lab-created diamonds article, and just for reference, here is a sample GIA report for a lab-created diamond (note the comments section):

Laboratory-Grown-GIA Report

So if you’re still wondering:

Is GIA the Best Diamond Certification?

That’s a no-doubt, there are many other well recognized labs in the market like AGS and IGI, but when it comes to the best diamond certification, and the lab that’s very strict when they asses a diamond, GIA comes first as the best diamond certification lab.

We’re not saying that other labs are not good (some of them are actually, like EGL, we recommend to NEVER get a diamond with EGL certificate), if AGS or IGI aren’t trustworthy, sites like James Allen or Blue Nile would never add their graded diamonds in their online store.

The thing is that GIA is the standard, they literally “invented’ the 4Cs that are used every single day, by almost every lab.

Where I Can Buy GIA-Certified Diamonds?

You can find GIA-graded diamonds almost anywhere, in your local jewerly store, Amazon, online diamond stores, and out of all these, we recommend the following 3 stores:

1- James Allen: Being the largest online store (surpassed Blue Nile since 2019), the leader in advanced diamonds imaging technology with 360-degree HD images, along with the latest SuperZoom feature that allows 40x magnified zoom, you can find no other place to see & inspect your diamond before buying it, click the image to browse hundreds of thousands of diamonds on James Allen.

Diamond Sparkle James Allen

2- Blue Nile: The store that revolutionized the diamond shopping industry back in 1999, with hundreds of thousands of diamonds (most of them have 360-degree images), you can find whatever diamond you want, even with very low carats, click the image to browse to browse Blue Nile collections.

Blue Nile Ring 2

3- Whiteflash: Well-known for their A CUT ABOVE® Hearts & Arrows collection, Whiteflash provides unique & outstanding diamonds quality with their premium collection, besides that, they have thousands of GIA-graded diamonds as well that you can shop by clicking the image.

How Can I Submit a Diamond to be Assessed by GIA?

A diamond owned by you can be submitted to the GIA for grading. The institute will go ahead to create a full report outlining all information on its cut, clarity, carat amongst other qualities.

The report is not free of course, and its cost depends mainly on the carat (weight), it starts from $48 for diamonds with carat between 0.15-0.22, keep in mind that we are talking about the “Grading Report” as GIA offers many other reports, like Origin Report, Dossiers, and others, you can check them & the fees for each report here.

Submitting the request is fairly easy, just head to their “Submit a Gem” page, select diamond type (Natural, Natural Colored, Lab-Grown, etc…), follow the step-by-step process in the wizard to get your diamond submitted for a certification.

But you may ask, why would I need to resend a diamond to GIA, which already has a GIA report? Honestly, in most cases you don’t, but people sometimes prefer to update the report if it has been issued long time ago, or they want to get a verification on the report you already have, and in some cases, if a diamond has been re-cut, people resubmit it to get a new report.

Read: EGL Vs. GIA Diamond Certification: Detailed Comparison

The report is obtainable when you run analysis on the diamond, letting you know exactly what you’re looking at and why it is worth its stated amount. It’s an amazing way to find out information about your diamond from an impartial point of view.


It is important to note at this juncture that you should always try to purchase a diamond with a GIA certificate. Understand that there is a difference between GIA certified diamond and a diamond that has been certified by a GIA trained gemologist.

In the first instance, the diamond needs to be graded by a GIA independent facility and issued a grading by the GIA to back the quality of the diamond.

While in the latter case, the diamond has been graded by a jewelry store employee who has been trained by GIA. The diamond has no GIA certification, and it is most unlikely that it was graded in accordance with GIA strict standards since these stores don’t have access to advanced grading & inspecting tools.

The gemstone seller may make great verbal recommendations and quote a big price but always confirm its originality with a GIA certificate. Request for a copy of the GIA Grading Report for any diamond you are considering. It is your stamp of quality.

Or even better, always buy from a trustworthy online store like James Allen or Blue Nile (and read out here why!)

Find the One James Allen

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