The purpose of all Diamond Certificates is to essentially describe the diamond itself by explaining its strong points as well as any flaws that the stone may have. To do this, a gemological lab will use different instruments to measure and otherwise investigate the jewel so that they can describe its condition for the person requesting the certificate. Experienced Diamond Graders are the people who create the certificates and they practice a skill that takes many years to master. They have been trained to thoroughly check any diamonds for the most minute of details in order to determine what the stones could be worth to those purchasing them. It is very important to have an independent gemological expert examine any stone you buy or intend to buy because if your certificate comes from the jeweler you bought the diamond from then it could, of course, be subject to a level of favoritism that may slant in favor of a higher price. The same is true in reverse if you are looking to sell a diamond.

It is important never to purchase a diamond that does not have a certificate because otherwise there is no real way to tell the worth of the stone since most details that lower its value are either barely visible or entirely invisible to the naked eye. You need an independent expert to verify its quality. All of the world’s most famous diamonds in the world have their own Diamond Certificates and this includes such renowned gems as The Tiffany, The Incomparable, The Millennium Star, The Hope Diamond, The Premiere Rose and The Heart of Eternity.

Two things that you will find on all Diamond Certificates are a number and a name of the lab that scrutinized your stone. Firstly, you want to make sure that you have either heard of the lab in question or that research proves the lab exists and is actually qualified to judge diamonds. Frauds exist in diamond trade as in any other area of business, so be cautious and sensible. The Certificate Number is the unique number given to your diamond by the lab that examined it. If you ever have questions, you should be able to contact the lab and use this number to reference the jewel so that they can give you an extra information or simply confirm their appraisal of it. On a Diamond Grading Report issued by the GIA, you will find a laser inscription of the GIA Report’s number as an added security measure.

The certificates themselves also feature plenty of other information such as the cut and shape of your diamond. The arrangement of the facets is referred to as the ‘cutting style’ and examples of what you might see include: Princess, Emerald, Step, Marquise, Brilliant and Mixed, which indicates various styles of cut were combined to  create the stone. Shapes can vary from Oval or Pear to Round or even Heart. In combination, on Diamond Certificates, you might see a stone defined as Round Brilliant or Heart Princess.

The measurements of your diamond will also be shown on its paperwork and this is normally calculated in millimeters. A micrometer is the tool used to take the measurements and it is accurate within one hundredth of a millimeter. Depending on the shape, the measurements are calculated differently. The more fancy types of shapes are calculated by multiplying the diamond’s length by its width and its depth. For round stones, the calculations are determined by subtracting the maximum diameter from the minimum diameter and multiplying that sum by the stone’s depth. The size of a diamond is measured with a digital scale accurate to one hundredth of a carat.

Both the color and clarity of a diamond are determined in the lab setting by comparing the gem to an array of diamonds laid up beneath a special type of lighting that helps to emphasize the points being examined. When it comes to color, the grades range from Z being least desirable up to D which is most sought after level of color. Stones with a rating below Z are considered to be showcasing ‘Fancy Colors’ and can be valuable in their own way due to these shades. Clarity, on the other hand, uses a completely different scale that goes from worst to best: I3, I2, I1, S12, S11, VS2, VS1, VVS2, VVS1, all the way up to IF, the highest grade for clarity that a diamond can receive. Irregularities on the surface of a stone, along with any natural inclusions within it, are examined using a Stereo Microscope. Fluorescence is an additional measurement that is gauged by testing the way that the stone reacts to long wave ultraviolet radiation. To some, a strong Fluorescence is considered a negative value. 

Finish, Polish and Symmetry are three other aspects of a grading that will be displayed on Diamond Certificates. These points all place judgment on the skill of the stone cutter themselves. Very evenly placed facets on a stone with an excellent Polish are said to have a high Finish. The Polish rating describes the level of skill and effort applied by the diamond cutter in making the stone shine, where as the stone’s Symmetry describes its facets and how precisely they are arranged to reflect the desired appearance of ‘mirroring’ one another by being properly placed and of equal size.

Along with all of these factors, Diamond Certificates will also include a graphical illustration of the stone called a Plot. Since all diamonds are as unique as snowflakes or fingerprints, the Grader at the gem lab can use this Plot to verify a stone they are shown is the same as the stone shown on the certificate. Plots use green ink to show external characteristics such as a cut, but red is used to show internal details within the stone. Your certificate should have a key to the symbols used on it for identifiers like minor errors in cutting or other issues. 

While the GIA’s Diamond Grading Reports show a picture of the diamond that explains its unique Proportions, other Diamond Certificates will have specific sections just for this information. The depth shown is determined as a percentage, measured from cutlet to table and this value is relative to the diamond’s width. The largest facet, which is what the viewer primarily looks at from above the stone, is crucial in determining the worth of the stone’s cut. The cutlet, it is the narrow end of the stone that is intended to help it keep from chipping. The final aspect included on some certificates is called the Girdle. This is the area that divides the top part of the stone, called the crown, from the bottom part of the stone, known as the pavilion. This aspect is described in terms of a range since it can vary around the diamond itself. Sometimes the Girdle is laser inscribed with messages, particularly if the diamond is a gift. 

Lastly, many comments generally appear on these documents as the Grader attempts to explain all the various intricacies of each stone and what makes that stone truly unique. Diamond Certificates, you should keep in mind, do not give a value for the stone. They are merely used to identify and record each diamond and give an appraiser a general idea of what they might be worth.