You’ve probably heard Juliet’s famous line, “a rose by any other name would smell as sweet.” But does the same apply to diamonds? Let’s say the diamond you’re looking at comes with some papers that say it is a G/VS2 quality stone. Isn’t that good enough? Well, it depends. As you’ve looked for your perfect engagement diamond, you’ve no doubt seen dozens of gem labs that issue diamond certification. But, are all gem labs made equal? The answer is a resounding NO.

Below, you’ll learn about:

  • What Diamond Certification is
  • Why Diamond Certification is important
  • If Diamond Certification affects value
  • Who issues Diamond Certifications
  • If all Diamond Certifications are equal
  • 3 reasons you really want a GIA Diamond

Note!! This post is about diamond certification for Natural Diamonds. Learn here about Lab Diamonds vs Natural Diamonds – and why we also recommend GCAL and IGI in addition to GIA for Lab Diamonds.


What is Diamond Certification?

  • An independent, scientific analysis of your diamond’s quality.
  • Appraisals and jeweler-written documents are not certifications!

Diamond certification is a process where an independent gem lab (one that’s not in cahoots with the jeweler!) tests and assesses the quality of a diamond. Then, the lab issues a written report about the diamond. Each report, or “certificate,” has its own number which is kept on file at the gem lab and a copy is sent back with the diamond. Also, many certified diamonds include a microscopic laser inscription of their certification number on the outer edge of the diamond (its “girdle”). This is helpful if a diamond certificate is ever lost or stolen.

loose diamond with inscription on edge of diamond

GIA Number Laser Inscribed on the Girdle of a Loose Diamond.

Most diamond certificates include the following grading categories:

  • Natural or Lab Created Status
  • Color
  • Cut
  • Clarity
  • Carat weight

Some diamond certificates will include a diamond “plot.” A plot is a drawing of the internal marks (or “inclusions”) of the diamond. In other words, this is your diamond’s fingerprint! Others do not include plots, to save time. In addition, certain gem labs include their opinion of the diamond’s value. Other labs refuse to value the diamonds they test, preferring to keep their reports impartial.

Pro Tip! Appraisals and other documents written by a jeweler are NOT diamond certificates. Most jewelers and appraisers do not have access to the testing equipment gem labs have. So, appraisals, or the word of your jeweler, cannot take the place of a diamond certification. 


Why is Diamond Certification important?

Diamond certifications are important for three big reasons. Firstly, a diamond certification proves the stone has been tested and has been confirmed natural. Secondly, credible diamond certifications (more on that below) prove diamond quality. Thirdly, diamond certifications help to put a diamond buyer and a diamond seller on equal ground.

Diamond certification proves it’s natural

Gem labs have access to a bunch of testing equipment that jewelers and appraisers do not. For example, while most appraisers have common tools, they typically do not have a way of testing for lab created diamonds or diamond treatments. So, a diamond certification proves the stone you’re buying is natural and not lab made.

Diamond certification proves quality

Diamond certifications are important as they are unbiased opinions of diamond quality. Grading between different jewelers and appraisers varies wildly. In comparison, gem labs have consistent diamond grading techniques. In other words, reports generated by jewelers and appraisers do not have the accuracy or trustworthiness of diamond certifications.

As we discuss in more detail below, some gem labs are more strict than others in these guidelines. The best diamond certifications, those we call “credible” diamond certifications, honestly and accurately describe the quality of your diamond. So, a credible diamond certificate is the best way to get what you pay for.

Diamond certification levels the playing field

Diamond certification also helps diamond buyers and sellers compare diamonds. It is important, therefore, that the diamond certificate you choose is credible. It is a diamond expert’s job to know the “ins and outs” of diamond quality. On the other hand, most diamond buyers are new to diamond grading. So, customers use diamond certificates to level the playing field. As small differences in diamond grading can make hundreds or even thousands of dollars’ difference, the credibility of a diamond’s certification is huge.

Hot tip! In addition to helping you choose a beautiful diamond for your engagement, making sure you choose a credible diamond certification will help you later if you and your partner ever choose to upgrade your diamond for a special anniversary, or gift it to your children. A credible diamond certificate lets others know exactly what they’re getting!


round diamond on top of gia certificate

A loose diamond with a GIA certificate.

Is a diamond without certification fake?

Not all diamonds come with certificates. So, just because a diamond does not have a certificate, does not mean that it is fake. On the other hand, a diamond certificate does prove that a diamond is natural!


Is a diamond without a certification worth less?

In theory, no, in real life, yes. Remember, a diamond certificate cannot magically change the quality of your stone. So, a diamond certificate, in theory, shouldn’t change the value of a stone. But, in real life, where we live, not having a diamond certificate can hurt you.

Without certification, there is no unbiased proof of the quality of your diamond. This makes your stone difficult to resell, loan against, or replace in case of loss. As a result, buyers, investors, and insurers do not value diamonds without certifications as highly. A diamond engagement ring is one of the most expensive, emotional purchases you’ll make in your life. Choosing a stone with a diamond certificate protects your investment!


Are all Diamond Certifications the same?

  • Not all Diamond Certifications are trustworthy.
  • Only labs that grade diamonds strictly protect your investment.

Ah, the $64,000 question! No! Diamond certification is a business. And, like all businesses, there are ones you can trust, and ones that just take your money. Diamond certification is not a regulated industry. In other words, there are no laws governing who can be a gem lab, who can write diamond certifications, how diamonds need to be tested, or what acceptable variations in grading quality are.

This lack of laws has created two types of diamond certifications: strict and lax. The strict labs, GIA, AGS and GCAL, test and grade diamonds against strict guidelines. The more lenient labs, like EGL and IGI, are looser in their grading. In addition to these well known labs, there are a bunch of smaller ones also offering diamond certifications…GSI, GGI, AGI…Old Mac Donald had a farm, EIEIEO.

Values on diamond certificates

  • Don’t trust a certificate that lists a diamond’s value – that’s a red flag!

The most credible diamond labs use strict guidelines to assess and grade your diamond. In other words, the only thing credible labs do is scientifically test and grade your stone. They do not put a value on your diamond. So, beware of certifications which list a value. These values are always inflated to trick you into thinking you are getting “a steal” at the retail price. But, they are not worth the amount of money listed on the certificate!

Labs that include values on their certificates often also “upgrade” diamonds. In other words, they give diamonds a higher quality grade than the stones actually deserve. Certification cannot magically make your stone a higher quality. Upgraded certificates, therefore, are not credible. As we discussed above, one of the big reasons you should choose a certified diamond is to protect your investment. Choosing a reliable, credible diamond certificate is the best way to ensure the value of your diamond.


What are the best Diamond Certifications?

  • GIA, AGS, and GCAL are the best labs.
  • GIA is the most well-known, well-respected diamond grading laboratory.

There are dozens of gem labs and So. Many. Letters. to keep straight. Some gem labs are independent, whereas others work for jewelers. Some have firm grading policies and hold themselves to strict professional ethics, like GIA, AGS, and GCAL. Others grade large quantities of diamonds quickly and inexpensively, and are therefore less strict.

Let’s explore the big ones.

GIA – Gemological Institute of America

GIA is held by all (literally) to be the industry gold standard. They have the strictest grading ethics, research diamonds and gemstones everyday, develop tools for diamond testing, and train graduate gemologists (GGs) throughout the world. Because of their famous high quality grading and sought after certifications, many other labs claim they grade “just like” GIA. Don’t let them kid you. They do not. GIA diamond certificates offer you the best grading and most protection for your special investment.

AGS – American Gem Society

Another strong choice for diamond certification is AGS. AGS uses strict guidelines and is well respected in the jewelry industry. Their cut grading system is praised by most jewelers. However, their color and clarity grading scale is different than GIA, with AGS using a system of numbers and decimals instead of GIA’s standard D-Z color and FL-I3 clarity scale. Although certainly credible, some people find this system confusing, and so these scales are not as well accepted as GIA’s.

GCAL – Gem Certification & Assurance Lab

Relative newcomer GCAL came onto the scene in 2001. GCAL has a zero-tolerance grading policy and backs its reports with a guarantee to stand up against other labs. It is not as well known as GIA, but is a strong choice for gem certification.

IGI – International Gemological Institute

IGI is a collection of labs with locations throughout the world. The consistency of IGI’s grading for natural diamonds varies between these different global labs. IGI’s grading of natural diamonds is a bit looser than GIA, often 1-2 grades off in color and 1 grade off in clarity. In terms of lab diamonds, it has been our experience that IGI is consistent and generally trustworthy. IGI was among the first gem labs to issue grading reports for Lab Diamonds, and they seem to have taken the task seriously.

EGL – European Gemological Laboratories

EGL is not one lab, but a collection of independently owned franchises. Reports from EGL USA are more loose in their grading than GIA, and are not as well respected. Diamonds from EGL USA are typically upgraded at least one, and maybe two, quality grades above a diamond’s true quality. For example, in a stone GIA would grade H/I1, EGL USA may grade the stone a F/SI2. As such a jump in color and clarity could mean spending thousands of dollars more. Wouldn’t you want to get what you paid for?

EGL International’s reports are widely accepted to be unfairly upgraded, sometimes ranging upwards of four or five grades off from than a diamond’s actual quality. EGL International’s reports are so far off GIA standard, in fact, that lawsuits have been initiated on fraud grounds.

At Do Amore, because we want you to get what you pay for, our Natural Diamonds all come with GIA certificates. I’m also very happy to perform a custom search for couples who prefer AGS or GCAL diamonds. Contact me here!

wooden engagement ring box in front of GIA diamond grading report

A GIA-certified diamond engagement ring.

The top 3 reasons you should choose a GIA Certificate

1. GIA is credible

You want to get what you pay for. And you want to know what you have! GIA does the strictest diamond certification out there. So, there is no question that the diamond grade on your certificate is the actual quality of your stone. No hemming and hawing. There will be no needing to argue that “it’s just as good as…”. Choosing diamond with a GIA certificate means you have independent, unbiased proof of your diamond’s quality, from the gold standard lab.

2. Everyone knows and respects GIA

A GIA diamond certification is recognized and respected as the best. This ring is one of the most important purchases you’ll make in your life. Choosing a diamond with a GIA certificate ensures that your partner (and your insurer!) knows exactly what’s on her finger. Also, in the event you want to upgrade or pass down your diamond to a beloved child, a GIA certificate offers unchallenged proof of the quality of your stone.

3. A GIA certificate protects your investment

When you go to insure your ring, your insurer will know and trust GIA. So, in the event of loss or theft, you’ll get max value back. Also, in the event you want to sell your diamond, the most desired diamond certification is GIA, ensuring you’ll get the best price.


I have more questions!!

Have more questions about diamond certification? Or, want help understanding or choosing the perfect certified diamond? Send us a note here, or email us at [email protected] and Do Amore’s GIA graduate gemologist will happily discuss diamond certification benefits with you!