4 Diamond Labs to Avoid (Should You Only Trust GIA?)

Last Updated on August 29, 2023 by Juli "Jewels" Church

Gemological labs popped up in the diamond market as a third-party entity providing diamond certification.

They are spread all over the world and each lab has its own way of grading diamonds. So, the big question is...

Who sets the standards? 

Since each lab produces its own legitimate grading certificate, there should be an organization (like the FDA) standardizing these reports.

Currently, there’s no such organization and this creates an opportunity for shady labs to thrive in.

diamond labs to avoid

But that doesn’t prevent great gem labs from existing. In fact, I have a whole page outlining the best gemological labs and why you should insist on them. So for you to get a diamond that’s worth the price, you’ll have to do away with bad grading reports. 

In this piece, I’ll point out suspicious gemology labs and why you should keep off them. 

Why Is Diamond Grading So Crucial In The Market?

Firstly, diamond grading is not similar to hallmarking where the value of a stone is equivalent to its contents only. It’s where the value of a diamond is determined by its physical and optical properties. 

Now, since there’s no one lab considered to have a gold standard of measurement, shady labs tend to get away with cheaper reports. Of course, these reports are inconsistent and the values are often questionable. 

EGL is known to produce stones that are inconsistently graded: some up to three levels! Remember a single mistake in grading a diamond can cost you thousands of bucks, so identifying mediocre grading labs will be a huge money saver.

Labs like GIA are reputable entities having thorough grading processes and experienced staff. A certificate from GIA will most likely be more precise than that from EGL. 

Read also: What are the top places to buy lab diamonds online?

Can You Trust The International Gemological Institute (IGI)? 

IGI gained its reputation when it started to certify major jewelry stores in Canada and the United States. With cheaper diamond grading certificates and fast turnarounds, the company became a popular brand in diamond chains. Even with major stores on its client list, IGI still fails to produce accurate reports and they have a laid back approach when it comes to grading.

You can always expect to find IGI with a couple of inconsistent grades in its specifications. It’s better to go with GIA or AGS certified diamonds. As a rule of thumb, your diamond should be worth the price, even when you bargain. I’ve also realized most IGI certified diamonds sell at unusual discounts (red flag alert!).

Can You Trust The European Gemological Society (EGL)?

Another gemological lab with lots of incidences of over-grading and inconsistency is the EGL (European Gemological Society). They also have EGL USA where most EGL certificates in the US come from. Looking at diamonds certified by EGL, retailers tend to have them on offer at cheaper prices. However, EGL is known to exaggerate grades and more often these stones are sold to unsuspecting shoppers.

I’ve seen a great deal of customers going for EGL diamonds and then later realizing the huge mistake they’ve just made.

For instance, in a reported lawsuit, one customer claimed to have been robbed thousands after buying diamond cufflinks worth $135,000, yet actual reports evaluate the stones at $22,500. The carat weight and clarity were the same, but the variations in color and cut had a massive impact on the overall price. You might want to read our article on the cost of VVS diamonds as well as other diamond clarities to get a better grasp on diamonds in general.

What makes this company so unreliable is that it uses similar terminology to GIA reports, yet when you compare the two certificates, the values are way off! It is better off going for lower grades in GIA buying an over graded stone.

Finding diamonds from companies like James Allen or Blue Nile is the most preferred choice. Diamonds sold at the two online jewelers have GIA certification (if not AGS). A few loose diamonds at Blue Nile may have IGI certification, but it is best to steer away from them or filter to GIA/AGS certified diamonds.

Can You Trust Gemological Science International (GSI)?

While GSI (Gemological Science International) is a freshplayer in the diamond market, the fail to surpass, or even meet standards labs like AGS and GIA have set. GSI is widely known in the United States and has certified diamonds from giant retailers like Kay and Zales.

GSI Grading Report

GSI’s grading is not only looser than giant grading labs but also goes below the grades of IGI. It also doesn't have a separate report, just a mini card like above. Honestly, that’s way too risky! You should avoid GSI graded diamonds and go for accredited labs like GIA or AGS. 

Should You Trust In-House Certification?

Diamond owners outsource third-party labs for grading/certification so that when it reaches the retail store, prices are set according to these grades. Some retailers offer in-house certificates where they grade their own diamonds. You’ll notice in this case, there’s no independent party involved in grading the diamonds (red flag alert!). 

If you think about it, in-house certificates can be a lot shabbier than those from gemological labs I’ve mentioned earlier. In-house certification lacks the scrutiny of an unbiased third-party and the company may decide to grade according to how much they want, rather how valuable the stone is.

It is also easy for companies to throw in popular terminology (Super Ideal Cut, VVS1, H-color, etc.) used in grading reports to cover up flaws or exaggerate the qualities. Always be careful whenever the deal is too good, and if possible avoid huge discounts and buy your diamond for what it is worth.

The Bottom Line About Diamond Labs...

When it comes to checking the quality of a diamond, its value will only be as good as the grading report. A grading report should guarantee accuracy and credibility.

Given the discrepancies of the above certification labs, I would suggest using GIA and AGS labs as the standard caliber for grading your diamond. So whenever you go shopping online, always check for the issuer of the grading certificate before you purchase a diamond.

gia cert report

Avoiding these labs means buying from the right diamond vendor. Jewelers like James Allen has almost 200,000 GIA certified stones and would be a great place to start diamond shopping. Such vendors not only have trusted labs, but you’ll get other services including free shipping, warranty, etc. So, as long as the certificate is from AGS or GIA, you’re good to go!

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