Diamond Grading Reports

Knowing about the different  grading reports that are available is important for anyone searching for a diamond. Even though laboratory reports are done independently from the diamond seller, each laboratory can vary greatly with different grading results. This can dramatically impact how much you pay for your diamond. Understanding these reports helps you make an informed purchase.

Knowing how the different laboratories grade diamonds is an important first step towards understanding the reports. The four most popular reports come from the Gemological Institute of America (GIA), the American Gem Society (AGS), EGL USA, and the International Gemological Institute (IGI).

Gemological Institute of America (GIA)

Trustworthy Grading & Strict Standards

GIA is the oldest, largest, and most prestigious diamond grading laboratory. GIA is known for creating the common grading system known as the 4 C’s, which include cut, color, clarity, and carat. The system created a universal language for diamonds, and is still in place today.

A grading report is a scientific report for the quality characteristics of a diamond. While grading reports are always considered when making an appraisal, the report itself isn’t an appraisal. A diamond grading report from GIA acts as official documentation of the authenticity of a diamond and ensures a diamond is natural, and hasn’t been otherwise enhanced for better color or clarity. GIA’s reports provide clear, definitive information that helps make a confident purchase.

A report from GIA is centered around the testing results for cut, color, clarity and carat weight. The reports also contain an in-depth plotting diagram that clearly shows the diamond’s inclusions and blemishes. All GIA reports will also contain unique security features such as microprint lines and a holograms to prevent forgery or duplication.

As a prestigious diamond research and educational institute, GIA doesn’t sell diamonds or represent diamond sellers in any way. GIA prides themselves as being an independent and impartial entity for diamond information. They employ hundreds of diamond experts, and are a reliable source for diamond reports.

American Gem Society (AGS)

Trustworthy Grading & Strict Standards, 

The American Gem Society was actually founded by Robert Shipley, who also founded the GIA. The AGS meets the same standards as the GIA does, but they also provide a more detailed report regarding the diamond’s cut.

The American Gem Society uses eleven criteria when evaluating the cut of a diamond, based on a 0-10 scale. 0 is the best  cut, while 10 is the worst. Beyond cut, the report is very similar regarding color, clarity, and carat of a diamond.

Trained gemologists, experienced shoppers, and top jewelers alike rely on AGS reports, and view them as the highest standards in diamond grading. If you agree with many experts that cut is the most important of the 4 C’s, the AGS might offer more valuable reports for you.

EGL USA

Less Strict Grading & Less Standards

Some jewelers prefer EGL grading on diamonds because their reports are more generous, making diamonds appear to be a higher quality and a better value. However, their standards are not as strict, so an EGL stone may not actually be of the same quality or value as a GIA or AGS graded diamond.

High standards and consistent grading is crucial for a good diamond grading laboratory. The EGL is generally known for soft grading and lower standards. Our recommendation is to stick with a GIA or AGS diamond grading report.

International Gemological Institute (IGI)

Less Standards

The IGI is a lab and school of gemology that grades diamonds for large diamond chain stores. Most high end jewelers don’t use IGI certifications due to their reputation for having lower standards than the prestigious labs of GIA and AGS. Still, the IGI offers their reports in varying formats to accommodate needs in international markets, and is well known for their diamond education.

Our Recommendations

When searching for diamonds online, ensuring report accuracy needs to be the number one priority. This helps to determine how much value a diamond should really have, and allows you to know exactly what you are purchasing. Some labs are strict and consistent, while other are loose and inconsistent.

If you’re purchasing a diamond online, the GIA and AGS diamond grading reports are highly recommended. These two labs are the most accurate, consistent and respected.  They are the gold standard of the industry..

For more help with interpreting diamond reports and determining the true value of a diamond, R.H. Bockstruck is here to help.