Diamond Certification: A Complete Guide

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Diamond Certification: What is This?

In essence, diamond certification is the scientific analysis of a diamond provided by an independent laboratory. The main purpose of the report is to verify that grading has happened so that you can see in numbers and facts what you’ve bought. Because of that, diamonds certified are considered as the only reliable gemstones for purchase in the diamond industry.

To support the grading completion, the institute gives you a special document. This report has the certificate number that proves the credibility of your diamond and tracks all its key grades and characteristics. Thus, many people (both experts and non-experts) rely on grading and certification to confirm the quality of your diamond purchase.

If diamonds are certified, they not only have a certificate number but also contain a girdle. A girdle is the microscopic laser inscription on the surface of a certified diamond with its grading number. With it, you can prove your diamond certification – even if you don’t have your report in the paper. That’s why the certificate and the girdle are two important elements of the certification process.

Which characteristics does the diamond certificate include?

The typical list of things mentioned in a diamond certificate is the following:

  • Diamond Status – whether it’s natural or lab-grown,

  • Diamond shape – it can be, for example, emerald, round, pear, or oval,

  • Diamond’s diameter,

  • Carat weight – note that 1 carat of diamond weight equals 0.2 grams,

  • Clarity grade for diamond – the exact mark can reach from Internally Flawless (IF) to Included of degree three (I3) grade,

  • Diamond color – the grading ranges from D to Z,

  • Diamond fluorescence – the parameter that indicates the reaction of your diamond to UV radiation exposure,

  • Diamond culet – the presence of the pointed part at the diamond’s bottom,

  • Proportions of a diamond – percentages of depth (the measurement from table to culet) and table (flat top surface),

  • Diamond polish – the quality of polished facets,

  • Diamond symmetry – extent of precision of the facets, compared to each other,

  • Diamond plot – the illustration of diamond’s imperfections.

At the same time, this grading report can have different elements, depending on the certification institute that issued it. There are some typical graphs in it, though. Among the essential diamond certification categories, 4Cs (color grade, clarity, cut, carat weight) are the must. In addition, you should check the category “plot” in the diamonds certified to see the overview of all the internal marks and inclusions.

Besides, you can request an authenticity assessment of diamond value from the expert. This will support the grading results and contain the necessary clarifications to read the certificate.

What’s the point of getting certification of your diamond?

The short answer is trust.

With the diamond certification, you see that professional gemologist approves the quality of your gem, including the accuracy of color, clarity, and cut grading your seller announces. Without a diamond certificate, you can’t prove that your diamond isn’t fake. That’s why it better to get your diamonds certified and disregard all the options that didn’t pass the certification.

At the same time, don’t take diamond certification as the measure to improve the value of your diamond. Also, it’s not a procedure to increase its final price. That’s the status endorsement of your precious stone. If certified, diamonds get a quality label that justifies the value-for-money behind their price. Also, certification safeguards your diamond in the case of reselling and replacement.

So, certification protects the value of your diamond – both its current price and its chances for future investment.

What to pay attention to while reading a diamond certificate?

By learning how to read a diamond certificate, you can make an informed decision about your purchase, even as a non-expert. Specifically, diamond certification allows making three main conclusions about the diamond:

  1. It’s natural. The sophisticated equipment in laboratories allows making precise conclusions about the diamond origin. That’s why a diamond certificate always states whether your diamond is natural or grown in a laboratory. And this grading information is trustworthy enough to consider certificate as the basis for natural diamond buying.

  1. It’s credible. Being a third party, diamond certification institutes guarantee unbiased quality research of your diamond. In contrast, any evaluation that comes from jewelers and appraisers doesn’t have such a vote of confidence – due to the personal interest in getting higher prices above the accuracy of a diamond grade assigned.

  1. You and your seller are treated as equal parties. All the stakeholders have common ground due to the transparency of diamond certificate information and the overall certification process.

At the same time, the credibility of a diamond certification institute that issues the grading report is the crucial question here. It is so because the diamond certification can be by itself a victim of competing interests. In the situation of its overall deregulation, this industry has no laws and quality standards. In the given circumstances, these things are left within the personal responsibility of each laboratory. Some of them really care about their reputation, while others have problems with the quality of their diamond grading conclusions.

What are the most reliable diamond certification institutes?

At the same time, the evaluation for the diamond certificate happens in each laboratory in a different way. They have different approaches, reputation, and value assigned. There are seven main institutions that issue certified diamonds:

Also, there are lots of small institutes offering certification services for diamonds. But all of them have severe problems in terms of grading quality.

So, how to choose the place to get your diamonds certified? Here are some basic principles:

  • Pay attention to permanence. This criterion means that the grading approach to diamonds should remain stable and acceptable in the diamond industry. The exact grades assigned to cut, color, and clarity should survive the test of time, and the certification institute should maintain the status of the gold standard.

  • Compare the value from a diamond certificate with the actual price of your diamond. In other words, the diamond certification should justify the price tag, with all quality, cut, color, and clarity characteristics revealed and explained. At the same time, avoid certificates that put value for your diamond in numbers. This trick is a sign that your diamond is given a higher quality grade than it objectively deserves.

  • Compare the results of various certification institutes. Check the grades provided to the identical diamond in one parameter – be that color or clarity rating. You’ll notice how some laboratories tend to look through imperfections in some cases to increase the price of a diamond.

So, what are they, the most credible certification institutes for diamonds? GIA laboratory is the best of the best, and the second place goes to AGS. The bronze medal is for GCAL – the diamond certificate from this grading entity is a good compromise. The certification approaches from EGL, IGI, AGS, HRD, and GSI are also respectable – but already raise doubts.

Let’s check the grading approaches of each of these certification institutes in detail!

#1 GIA Certification

GIA, or the Gemological Institute of America, has the greatest reputation in terms of diamond grading. It was founded in 1931 as a non-profit organization to establish authority in the world of gems. In accordance with this purpose, GIA presented its grading system in 1953. Since then, it is taken as a quality standard for the diamond certificates. In addition, GIA is well-known for its ethical purity, extensive grading research, and comprehensive certification process.

The long-term maintenance of zero interest in diamond sales is one of the factors that support the unchallenged reputation of GIA. As another winning factor, GIA is extremely careful about its diamond color and clarity grading – the scales that require maximum attention and honesty. Many laboratories cheat at diamond color and clarity grading since they are hard to measure but influence the final price significantly.

Nevertheless, the certification institute doesn’t rest in ease of its high-quality reputation. GIA invests in its diamond grading machinery, research methods, and training of gemologists consistently. So, not only the certificates issued but also the professionalism of the grading experts make the grades from GIA so exceptionally reliable.

#2 AGS Certification

AGS, or American Gem Society, is another reliable place to get your diamonds certified. It is known as the first diamond grading institute ever to present its evaluation scale. This event happened in 1943. Precisely, the laboratory introduced the unique cut grade scale, which ranges diamonds from “0” (or “ideal”) to “9.” AGS was recognized by this achievement for long – before GIA launched its cut grades and challenged this favorable situation for AGS with competition.

To win the rivalry, AGS started positioning its results as more refined. Nevertheless, these claims are hard to prove in practice with the real diamonds. Many retailers see no difference between GIA and AGS and go for AGS from the force of habit. What people agree on is that it is the greater choice for perfectly cut round diamonds’ certification. Also, AGS commonly provides grading for diamonds of fancy cuts – like True Hearts.

In terms of diamond grading, AGS uses a different approach to cut, color, and clarity measurement. Precisely, the institute gives grades in numbers instead of words and letters. For AGS, cut grades range from 0 to 9 (instead of “Ideal” grade and “Poor” grade), color grades range from “0.0” to “10.0” (instead of “D” grade to “Z” grade), and clarity grades also range from “0” to “10” (instead of “Flawless” grade to “Included” grade) for diamonds. Frequently, these grades in AGS certificate have an opposite effect, confusing buyers and turning them to GIA instead.

#3 GCAL Certificates

GCAL, or Gem Certification and Assurance Lab, is a good alternative to IGI, EGL, GSI, and HRD. It appeared only in 2001, and, in contrast to the other institutions listed in this overview, didn’t play with upgrade with diamond color, clarity, or cut.

Also, it has zero interest in diamond prices, which makes GCAL more reliable than IGI, EGL, GSI, and HRD. If this certification institute maintains this reputation for decades, it can turn into another golden standard.

#4 IGI Certificates

IGI, or the International Gemological Institute, has a reputation of the working class in the refined world of diamond grades. It achieved this title thanks to the high speed of its certification process in combination with low prices for the service. However, this strategy made IGI more attractive for diamond sellers than diamond buyers.

Established in 1975, IGI positions itself as the most influential and non-dependent gemological laboratory. For this, it launched the chain with offices in all the key diamond centers, offering vast education and professional certificates to everyone interested.

In practice, IGI is the top choice for the most popular jewelry chains, including Kay and Zales. This fact reduces trust to IGI, as the institution is likely to start serving the interests of diamond retailers. Also, sometimes color and clarity grades from IGI are inaccurate, which shows that the institute doesn’t mind to “upgrade” some diamonds from time to time.

#5 EGL Certificates

EGL, or the European Gemological Laboratory, is the institution founded in Belgium in 1974. In its everyday activity, EGL is led by the purpose of maintaining a scientific approach to jewelry grading. In particular, the institution invests in applied research, novelty, and service of needs. At the same time, the price you’ll pay for getting an EGL diamond certificate is lower than the information about grades issued by other institutes.

Being the collection of numerous franchises, EGL functions under the rules of a business model in the diamond world. Therefore, the laboratory frequently plays with upgrades, especially when it comes to diamond color, clarity, and cut, to get more profits from its activity. As a result, EGL diamond even faced several lawsuits, accusing the laboratory of fraud.

That’s why EGL is not taken as a reliable grading institution for most observers.

#6 GSI Certificates

Being a freshly established grading institution, GSI issues diamond certificates for just a couple of years. Standing for Gemological Science International, GSI was also spotted on playing with upgrades of color, clarity, and cut. Also, collaborations with big diamond retailers are known.

Another big disappointment is the lack of innovation in the scientific approach of GSI. This makes it reasonable to state that GSI is a fair choice for getting your diamonds certified, but if possible, refer to other certification institutes from this overview.

#7 HRD Certificates

HRD, or Hogr Raad voor Diamant, is another quality certification institution based in Europe. Translated as “Diamond High Council,” this entity issues diamond certificates since 1973. In its activity, HRD works with the public and governments to deliver high-quality information concerning cut, clarity, and color grade parameters.

In general, professional jewelers approve the diamond certificates from HRD. However, many observers noticed some inconsistencies in grades in them. In particular, it’s common for HRD to put a couple of extra grades above in terms of diamond color and clarity. For diamond companies, this means allowing setting higher prices for their services – and favoring HRD for helping them.