Which diamond certification is best?

Any time you’re considering a loose diamond for purchase, it’s important that you consider its diamond certificates before closing the deal.

There are unfortunately many shady characters in the jewelry industry, waiting to take advantage.  Because of this, it has become increasingly hard to gain a customer’s trust, which is any reputable jewelers ultimate goal.

One hundredth percent transparency is our goal here at Jonathan’s.  That’s how we’ve sustained our business for the past 27 years. Our theory is that we’ll get more business if we educate our customers about diamonds, instead of trying to hard-sell.

That honest approach is what keeps our customers coming back over and over again while referring their friends and family as well.

While education is important from the jeweler’s side, it’s arguably even more important from the certification company that diamond shoppers rely on for an honest, independent assessment of their stone.

We always recommend GIA diamond certificates (for many reasons that we’ll list below), but most importantly – their entire company is based on diamond education.

Which Diamond certification lab is the best?


Our pick? Gia all the way! GIA stands for Gemological Institute of America, as is widely considered as the standard-bearer of the diamond certification industry. Everything that the GIA does is focused on education, whether it’s for the consumer or the jeweler.

An important factor that makes the GIA our top choice for diamond certificates is the fact that they are truly an independent, non-profit entity. Every diamond that is inspected by the GIA is viewed by four expert gemologists, and it’s impossible for jewelers to “game” the system by getting grades that are better than what the diamond actually is.

The process is fairly simple. Jewelers source the diamonds, ship them to the GIA, and then receive them back a few weeks later with grading certificates for each stone.

One of the biggest reasons that a jeweler may shy away from GIA certifications and verifications is the fact that it takes longer for a diamond to get through the GIA’s system.

Read also: GIA Certification: What’s the big deal?


AGS, or American Gemological Society, is considered as a high quality diamond certificate, and often draws comparisons with the GIA. While their process is scientific in nature like the GIA, their diamond grades tend to be slightly looser. This means that a diamond may be 1 to 2 grades off from what it truly is.

The AGS is the second most used diamond certification in the United States, and bills themselves as a sophisticated alternative to the GIA. Their process uses a 1-10 rating scale instead of a letter-based scale that other diamond certification entities use.


EGL stands for European Gemological Laboratory. Though not as prominent in the United States, the EGL is very widely used in Europe. There are two factions of EGL: EGL USA and EGL International. EGL International has been banned in the United States.

In our opinion, the GIA is vastly superior to the EGL International in terms of both non-bias and diamond grading. EGL USA is more accurate than the EGL International, but the GIA is typically more accurate than EGL USA.

Historically, EGL USA has shown that their diamond grades are slightly looser than the GIA’s grading standards.


IGI stands for International Gemological Institute. Like the EGL, this for-profit diamond certification lab is prominent throughout Europe, but is also popular in the United States. The biggest problem with the IGI is their laxed diamond grading standards.

IGI certifications can be as far as three grades off from GIA certifications. We highly recommend that customers avoid EGL and IGI diamonds if possible.


While all diamond certification entities range in their accuracy and grading systems – the most accurate is the GIA. Their ability to maintain independence from jewelers and their commitment to operate as a non-profit, educational organization is important.

Good, accurate certifications help customers know that the diamond that they are purchasing is exactly what the jeweler says it is.

Are you interested in creating your engagement ring with a loose diamond from our inventory? Contact Sergio@jfjco.com to schedule an appointment and find the perfect diamond today.

Want to see some examples of our work? Take a look at our engagement ring photo gallery and video gallery. You can keep up with Jonathan’s on Facebook, Twitter, and even follow our personal Instagram accounts below:

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Jay Freedman

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