This is because AGS reports assess cut quality on a stricter standard compared to GIA using an optical ray-tracing assessment which measures the light performance of the diamond. Most consider that in comparison, the AGS grading report provides more in-depth information related to the cut quality and light performance of the diamond. Instead of using an alphabetical rating system, AGS uses a scale of 0-10 for rating a diamond’s characteristics, with 0 as the best and 10 as the worst. The grading system used by AGS is similar to GIA and equally respected as a high-quality report. Members of the AGS subscribe to a high level of ethics especially with regards to education and consumer protection. Purchasing a diamond or gemstone with a GIA report should give you the best representation of your diamond’s true quality.Īlso headquartered in the U.S., the AGS was formed at about the same time as GIA with the focus as a trade association of jewelry retailers, independent appraisers, suppliers, and other industry members. The reports issued by GIA are highly respected for their stringent grading criteria and demonstrated consistency. It has offices in cities around the world and employs more than 1400 scientists, educators, and certified diamond graders. In the 1940s, GIA established the “4Cs” and the International Diamond Grading System™ – to this day, the worldwide standard for evaluating diamond quality. The GIA has operated for more than 85 years with its headquarters currently located in Carlsbad, California. The GIA is the leading gemological laboratory in the world and one of the industry’s most respected and trusted service. Here is a snapshot of the four biggest diamond grading laboratories in the world. However, it’s important to keep in mind that this explanation is a subjective opinion and that’s why it is important to know where the grading report originated. Buying a diamond from a jewelry store that offers a third-party grading certificate is critical to avoid a conflict of interest or bias in the grading. That’s why a grading report can be critical in figuring out if you are paying what the diamond is worth. As you evaluate diamonds or gemstones for the perfect diamond solitaire engagement ring, a grading report will give you an in-depth explanation of the quality of the stone and ensure you aren’t scammed by a treated or synthetic diamond. Although it’s described in varying terminology, the grading report will include a range of values for the diamond’s brilliance, cut or shape, any known treatments to the color or clarity of the stone, any inclusions, and carat weight. It is not an appraisal, which is usually used for insurance purposes to verify jewelry value but it can be a document that you can use to prove ownership. It confirms the stone’s authenticity and quality. What is a Diamond Grading Report?Ī Diamond Grading Report records in detail the particular qualities of a loose diamond or gemstone. The solution to overcoming this challenge is to learn a little more about what a grading report shows and the four best known gemological labs in the world that issue the certificates that you may encounter. What one certificate claims as “high-quality” may not be consistent with what another certificate claims. And that makes it even more difficult to make sure you are getting the quality of diamond that you are paying for. Each of these certificate issuers uses their own grading method and terminology. There are many grading laboratories and gemological institutes around the world that may give credence to the ratings that make up some of those “Cs,” but not all laboratories are created equal. Still, you may want to educate yourself not only about the well-known “4 Cs” of diamond quality - cut, clarity, color, carat weight, but also about the type of grading certificate that may accompany the diamond. That’s why having a trusted jeweler like Ben Garelick who has been in the business for decades on your side is a great start. Shopping for the perfect diamond engagement, wedding or anniversary ring is no easy task.