How To Decipher A Diamond Grading Chart

Diamond grading reports are primary way in which the jewelry industry ranks the quality of their diamonds. These reports offer up a great deal of information on the diamonds and are necessary to insure the stones.

Most jewelers recommend getting a diamond grading report when making a large diamond purchase to ensure transparency and accuracy in the transaction. Diamond grading reports are primarily concerned with the color and other physical aspects of the diamond - all of which play an important role in the stone's value. Diamond grading reports offer up a lot more in depth information about a stone than the traditional Four C's most of us are familiar with. A good diamond grading report will go a long way in addressing how the diamond's cut, carat weight, clarity and color affects the stone's specific value.

Here is what to look for when reading a diamond grading report:

1. A report is only as good is the lab that issued it.

   There are multiple labs that issue such reports, and it pays to be familiar with them all. The American Gem Society, or AGS, is renowned for their diamond quality reports as they offer up the best "sight unseen" descriptions in the business. This makes AGS reports perfect for online buyers. In-person buyers of diamonds, on the other hand, should consider diamond grading reports from the European Gemological Society (EGL) or the International Gemological Institute (IGI). Both of these organization are highly respected in gem grading circles and offer easy to read grading reports geared towards the average diamond buyer. International diamond buyers will want to consider reports from HRD, which is a Belgian organization based in Antwerp. The HRD is one of the most ubiquitous and respected diamond grading companies in the world.

2. Pay attention to the color grade letters.

   The most important bit of information in a diamond grading report is its color grade. This grade is denoted by a letter, and can be anything from D to Z. Any diamond with a grade in between D and F can be considered as particularly valuable, since that stone is virtually colorless and will fetch a higher price in any market. Diamonds graded G to I have a little color and can be made to sparkle as much as a clearer stone with the appropriate cut. Stones in the J to L range have a yellowish tinge, making them less valuable. Diamonds with ratings beyond L are considered to be of very poor quality due to their lack of sparkle or attractive color. It should be pointed out that diamonds whose color rating reaches the Z grade are considered to be quite valuable.

3. Read the comments section of the grading report carefully.

   This is where any issues not that cannot be numerically graded or rated are described in greater detail. The comments section can describe a stone's issues with clarity as well as any other non-obvious objections or praise. Diamonds with unique flaws that can heighten its value or a technically perfect, yet uninspiring diamond will be pointed out in the grading reports comments.

4. Keep watch for any reports on the diamond's anomalies.

   Besides detailed information on the diamond's cut, color, carat and clarity, many other things relating to the diamond are included in the grading report. The report might state, for example, if the stone has gone through any treatments, or if it has been laser inscribed. The grading report will include such details, as well as a plotting diagram of inclusions in the stone. This type of specialized information is not available from a vendor or jeweler, can help you uniquely identify the diamonds being graded.

5. Consider the diamond's fluorescence.

   A diamond's natural fluorescence under sunlight or artificial lighting can be an attractive property for some buyers, as it makes that diamond appear brighter in certain environments. This can be a double edged sword, however, since the fluorescence of a colored diamond can actually cause it to look muddy and dull. Always pay attention to the diamond's level of fluorescence in a grading report and look for what kind of an impact that could have on the stone's sparkle.