Diamonds FAQ: How to Read a Certificate Note: This page only covers certificates. For a more comprehensive list of FAQs, go to our Index of Consumer Questions page. According to the lawyers, GIA issues only a "Diamond Grading Report" and not a "certificate," warranty, or guarantee of any kind. But since everyone calls it a diamond certificate, we will continue to use that term here to avoid confusion. Always use a certificate from a reputable lab to compare diamonds and their prices -- and to avoid costly mistakes. IMPORTANT: Whenever you have questions about diamonds, rely on a good, honest jeweler for answers. We rated the best internet jewelers and created an exclusive network of the best local jewelers in most major areas -- so you would have somewhere to start your search for the truth about diamonds. REMEMBER: A dishonest jeweler can cheat you, no matter how much you know. And an honest jeweler will give you a great deal, no matter how little you know. Invest the greatest energy and time in finding a good dealer first, then you will always get a great deal on any diamond you want. Let the jeweler use their connections in the industry to find your diamond. ========== We Make It Simple ========== We have tried to be brief in this report while providing the details necessary to make the best decision about your diamond. If the information seems overwhelming, you might want to consider calling a good jeweler, and ask them to help you wade through all of it. It is always faster that way, and you will learn a lot more when you look at stones in person. And if you are ready to focus on calculating a fair and competitive price for your diamond, go to our Diamond Pricing Tutorial page. That guides you step-by-step through the fastest and most accurate way to price any diamond. ========== Print Sample Certificates ========== To make the most from this report, we suggest printing examples of your favorite lab certificate to follow along as you read the explanations below. Use these direct links to the samples of each cert on the official laboratory web sites: (these links are accurate as of Mar 1, 2012) GIA reports = Diamond Grading Report and Diamond Dossier AGS reports = Platinum Diamond Quality Document Diamond Quality Document Diamond Quality Certificate Diamond Quality Report Diamond Quality Analysis Diamond Consultation EGL USA reports = European Gemmological Laboratories USA (as opposed to EGL anywhere else) Please don't tell me you are using any other lab report. It would not make either one of us very happy in the end. Stick to these labs, please. FAQ -- Frequently Asked Questions ========== Q: ========== Do the same guidelines apply for smaller diamonds, like the ones that might be used for side stones? ========== A: ========== The answer depends on the size of the diamonds you use on the side. All diamonds above 0.46 carats in weight should be judged on the basis of the guidelines we have given in this report. Therefore, if you will be purchasing a 2-carat diamond for the center stone, you might want to design a ring with side stones that weigh about 0.50 carats each, or whatever looks in good proportion to your eye. In that case, the usual guidelines would apply. But keep in mind that some people put less emphasis on quality in the side stones. We recommend matching the color of the center stone, but perhaps considering side stones with somewhat less clarity. ========== Q: ========== Why a certificate? ========== A: ========== The value of a good lab certificate when buying a diamond is undeniable. If you do not receive a diamond grading certificate from an unbiased, independent, respected laboratory, you are not getting the diamond you are being promised. First, about half of all diamonds are overgraded by one color grade and one clarity grade -- to make them easier to sell. This may not sound like much, but for a 1-carat diamond it can easily mean $1,000 or more in lost value. A certificate from a respected, independent laboratory will give an accurate, unbiased assessment to help you avoid this problem. Second, every diamond is unique. This makes a diamond purchase very different from buying a brand-name automobile with a list of options you can look up in a price list. There is no comprehensive diamond price list because the list would have to include millions of possible combinations of weight, color, clarity, girdle thickness, etc. -- about 22 factors in all. Not even the well-known Rapaport price list is enough, since it only gives the basic starting point with prices for about 10,000 combinations of four best-known factors of shape, size, color, and clarity. If you try to calculate a diamond price from the Rapaport alone, without considering the remaining 18 factors that dealers use, you could easily be off by 30% or more and end up overpaying for a poor-quality diamond. An unbiased certificate supplies all the essential details and allows a complete assessment of a stone's basic value. Third, it would be very difficult and time-consuming for a layperson to learn enough to properly assess all the complex factors of diamond quality and pricing. It is not practical to take six months of in-residence training to become a gemologist for an item you only buy once in a lifetime. Without sufficient knowledge, you will certainly miss some tiny factor that means a great deal to the value. A detailed certificate saves you enormous amounts of time by supplying an expert evaluation. A diamond grading certificate from one of the better labs is the first, crucial step in getting what you want for fair price. ========== Q: ========== Aren't all gemological labs the same? ========== A: ========== Definitely not. Most smaller gem labs are extensions of local jewelry stores, created solely for the purpose of raising the image of the store's inventory. But such labs are hardly unbiased and the certificates are rarely accurate. To make it simple, if you want an honest assessment of a diamond's true quality, avoid any lab that is not one of those listed below: GIA -- Gemological Institute of America The most widely respected laboratory in the world today. Certs from this lab are in such demand that diamonds with a GIA cert are often priced 30-50% higher. This premium is also due to the fact that the diamond is truly the stated quality, since GIA is known for its conservative grading. All labs can make a mistake, but GIA labs have been the most consistent for decades. AGS -- American Gemological Society This was the only large, nationally respected lab that assigns a grade to the overall cut of a diamond. Now they all give cut grades, using varying criteria for each grade. More on that in my future blog, or the upcoming new website. Certs from AGS are often used for all Ideal Cuts, and describe all the details of the cut to verify perfect proportions. If you want a perfect cut above anything else, you should insist on an AGS cert. EGL-USA -- European Gemological Laboratories Several related labs around the world operate under this network. Please focus on certs from the EGL-USA network of labs. EGL certs from other labs around the world are NOT as reliable yet. The grades at the non-USA labs are not as reliable, and that reflects on the value of the diamond. EGL-USA labs are consistent in our opinion. AGL -- American Gemological Laboratory This lab is best known for its work in the colored stone industry, working to provide expert assessments of gemstone identification, treatments, and enhancements. The diamond certs have recently gained a reputation as consistent and conservative. IGI -- International Gemological Institute This lab is working to improve its reputation and grading standards, but it will take some time to convince us that the bugs are worked out. They tend to grade diamond higher than GIA, AGS, and EGL-USA. Note About Other Labs Other labs may be highly qualified and offer excellent information. However, other labs do not enjoy the same reputation and popularity as those listed above, and therefore will not command as much value if you ever need to sell the diamond. In the worst scenario -- and a very common one -- other labs will not grade the diamond properly and you are not receiving the actual quality of diamond you want. In most cases, you will end up paying too much for a diamond of lesser quality with certificates from other labs. ========== Q: ========== Are all diamonds priced the same? ========== A: ========== You should also understand that all stores price diamonds differently. Some have lower markups, some higher. Some have poor credit or low volume, so they pay more for the same diamonds and must charge more just to break even. Most stores have some combination of these situations, creating a wide range of prices for the same quality diamonds. The best proof of this is found on the Internet. If you search several different sites, you might find the exact same diamond listed by different companies. Many sites access the same national inventory from a common database. You will find that each store offers that diamond at a different price. If you want to know the best places to buy, read our independent Dealer Ratings. Back to: How to Read a Certificate