Diamond Evaluation Certificates: Do I Need One?

When you’re trying to buy or sell a diamond, you might hear a few abbreviations being thrown around in regards to diamond certification and evaluation. And if you’re like most people, your reaction will be something along the lines of, “what?” Buyers and jewelers like to talk about GIA, AGS and EGL, but what do those letters stand for? Who are these organizations and what do they do? Fortunately for you, the answer is simple. They are gem-grading institutes that can evaluate and grade a diamond’s quality based on a set of standards. So do you need one? And which one do you get? The answers to both are surprisingly simple.


Do You Need Certification?

If you’re selling your diamond jewelry through Diamond Lighthouse, the answer is no. Our expert gemologists, with over 25 years of experience valuating and grading diamonds, are trusted in the diamond industry for their fair and accurate evaluations. They will determine everything there is to know about your diamond and pass that information on to you along with an estimate of what we think we can get for it. Then, we take it to our network of elite diamond buyers and dealers, who don’t normally buy diamonds from the general public, and push them for the highest price. Because our gemologists are so trusted by the industry, we’re able to get you the most money for your diamond with or without a certificate or grading report. That said, having one certainly helps. If you are considering getting one, you have a few options available, including the GIA, EGL and many others. But which organization should you choose?


Hands down, the Gemological Institute of America is the way to go if you want to get the best value for your diamond. The GIA is the most trusted independent diamond evaluator in the industry because they offer the strictest, most accurate and most consistent grading reports in the business. Founded in 1931 by jeweler Robert M. Shipley, the GIA sets and maintains the grading standards by which diamonds are judged. They standardized the four Cs (cut, clarity, color and carat weight) as the metrics by which all diamonds are judged and graded. A GIA grading report does not give you a value, but it does tell you everything else about your diamond. If you’re selling diamond jewelry yourself, a GIA certificate will, in most cases, get you a better price. Secondhand jewelers are going to try to offer you the lowest amount they can. A GIA grading report levels the playing field. You know exactly what you have, they know exactly what their getting. It’s a lot harder for a secondhand jeweler to kick the tires (so to speak) when the all the information’s right there in front of them.

If you sell your jewelry through Diamond Lighthouse, we don’t require a GIA grading report. If you

already have one though, it can speed up the selling process significantly. We’ll be able to provide you with a more accurate estimate and even start getting offers from buyers before our gemologists even see your diamond. Our buyers will also be more confident in the quality of the diamond and in some cases, might be willing to offer a higher price.


Another organization you may have heard of is the American Gemological Society. The AGS is a trade association of independent jewelers, appraisers and suppliers. Also founded by Robert M. Shipley, the goal of AGS is to educate consumers and protect them from fraud and false advertising. Unlike the GIA, you can’t send your jewelry directly to the AGS to be evaluated. Instead, their website can help you find an independent and trustworthy appraiser in your state. The appraiser will use the AGS grading system. Unlike the GIA’s letter grading, AGS appraisers use a simple zero to 10 scale for each of the four Cs, with zero being the best and 10 being the worst. The appraisers may also provide you with a value, but keep in mind that the value an appraiser gives you isn’t what you’re going to be able to sell it for. Also, the appraisal value is likely to change very quickly as the diamond market fluctuates. The value they give you is what your diamond would sell for new, not what a pawn shop or secondhand jeweler will pay for it. While AGS appraisers are known to be just as strict and accurate in their appraisals as the GIA is in their grading reports, an AGS appraisal doesn’t carry the same weight that a GIA grading report does. A GIA grading report is the industry standard and their grading scale, as confusing to a layperson as it can be, is the most widely accepted way to evaluate and talk about diamonds. Also, since GIA grading is done by the institute itself, their evaluations well generally be more consistent. As strict as AGS standards are, grades are still somewhat at the whim of the independent appraiser.


If GIA and AGS are the first and second most trusted gem-grading associations, EGL-USA comes in at a distant third. EGL stands for European Gemological Laboratory. EGL-USA was originally just the U.S. branch of the EGL, but became independently owned and operated in 1986. EGL-USA’s diamond grading reports are generally more accurate than EGL International’s, but neither carry the weight that a GIA grading report or even an AGS appraisal will. That’s because EGL-USA is known in the diamond industry for being more lenient in their grading. EGL-USA uses the same language and grading system as the GIA, but because they have their own internal standards and methods, they can end up with wildly different results. While their standards have gotten tougher in recent years, the reputation persists, and it’s still fairly common for an EGL-USA report to be significantly kinder than one from the GIA. If you bought a diamond with an EGL certification, it’s a good idea to send it to the GIA to be sure of what you have. The GIA report will come in handy anyway should you ever try to sell it. Diamonds rated the same by both EGL and GIA often sell for up to 5 percent more when accompanied by a GIA grading report.

IGI, GIS and Others

Other gem-grading institutes exist, but it’s the same story as EGL-USA. International Gemological Institute, Gemological Science International and other gem grading organizations just aren’t trusted by the diamond industry the way the GIA is. As EGL-USA, they each have their own standards and methods that can make their outcomes vary. GIA is the agreed upon industry standard and a grading report from anywhere else is going to be met with some skepticism. Diamond buyers know that a stone that received high ratings from IGI, GIS or EGL-USA could very easily receive a much lower rating from the GIA and therefore not be worth as much. That’s why if you’re buying a diamond that comes with a grading report or certificate, it’s important to learn exactly where the report came from. If you see two diamonds rated equally, but one is from the GIA and one is from EGL-USA, the GIA-graded diamond is going to be the safer buy. And if the one from EGL-USA costs less than the GIA-graded stone, be very careful. In most cases, you aren’t getting a great deal, you’re getting a worse diamond.

As complicated as it is keeping all these organizations and institutes straight, you only need to remember one simple point: The GIA is the most trusted diamond grading institute in the business, and a grading report from anywhere else is going to come with some serious caveats.

If you’re buying a diamond, a certification from the GIA will give you peace of mind and let you know exactly what you’re paying for. If you’re selling a diamond, a GIA grading report may help you negotiate a better price. Or, you could call Diamond Lighthouse. While we appreciate a report from the GIA, we don’t require one. Our expertise and unique position in the diamond industry allows us to push our exclusive network of expert diamond buyers and dealers for the best price, no matter what certification you have. We will use every tool at our disposal to make sure you get the most money for your diamond.


Leave a Reply

Your email address will not be published. Required fields are marked *