Everything You Need to Know about Your Diamond’s Certification or Grading Report

Different aspects of diamonds are measured according to criterion from various institutions. The most common reports in the industry rank diamonds on many scales, and it is important to be familiar with them when purchasing a diamond.

Diamonds don’t just get gradings from one single entity. There are a multitude of institutions that claim to have the most accurate and consistent grading methods. A diamond certification from one institution is not necessarily equal to another. A report from one agency may raise the price of a stone, while another may not be reputable at all. Knowing which grade reports to focus your attention on will help you find the right diamond for you.

American Gem Society Laboratories

The AGS, also known as the American Gem Society Laboratories, has been a diamond grading institution for the better part of a century. Since the 1990s, they have operated as a non profit organization.

This organization uses a unique ‘cut grading’ method that no other diamond grading institution uses. AGS diamond reports are the simplest to understand in the industry, basing many criteria on visual impact. Proportion, size to weight ratio, light leakage, dispersion, and finish are all included in an AGS diamond certification. Oval, round, princess, emerald, and cushion cut diamonds are graded by this institution. A positive AGS certification can increase the price of a diamond, but generally has little impact.

International Gemological Institute

Another diamond grading agency is the International Gemological Institute. The IGI is the second most widely known diamond evaluation institution. Visual surface characteristics make up the body of these grade reports. Aspects like clarity and color are graded by the IGI.

However, the accuracy of a diamond certification from the IGI is widely debated. Many people find a high rating from the IGI to be very meaningful, and are willing to pay a premium. Others place no stock in these reports. Because of this, the price of a diamond is not affected by an IGI report. Be aware of the controversy when viewing these reports.

Gemological Science International

Gemological Science International is an extremely new diamond grading agency. The GSI is only a few years old and has made its name catering to large chain jewelers like Kay Jewelers or Jared’s. This agency gained momentum mostly by undercutting other institution’s prices to gain business from these chains.

In the industry, Gemological Science International grade reports are seen as inconsistent and inaccurate. Their grading is much looser than any other certification in the industry today. When looking to purchase a diamond, it is better not to take into account a grading or certification from the GSI. Due to this unreliability, prices of diamonds are not affected by any GSI grade reports.

Gemological Institute of America

The Gemological Institute of America, also known as the GIA, has the most accurate and consistent grading techniques in the industry. The GIA’s grading practices have become the global industry’s gold standard. The Gemological Institute of America is a not for profit organization.

There are two reports that the GIA will issue a diamond - a grade report and a diamond dossier. The only difference between these two is that a grade report includes a diamond plot, while a dossier does not. These are thorough certification reports, each with their own unique ID number. A corresponding number may be found on the girdle of any particular graded diamond. A GIA certificate will raise the price of a diamond as much as 25 percent, due to its accuracy and consistency. When purchasing a diamond, be sure to read the GIA report closely.

For more information or to begin a purchase, contact Long Jewelers at 757-498-1186 or visit our website.