Congratulations! You have just bought a diamond. Whether it’s for an engagement ring, or another piece of jewelry, if you bought it as a loose stone, it should come with a diamond certification. But what is a diamond certification and why is it important to have one?

A diamond certification is what tells you all about the diamond you just purchased. Think of it as the VIN number for your diamond. Now, not EVERY diamond comes with one, but they should, and if you are purchasing a diamond, be sure to ask about the certification. Diamond certification standardizes the industry by providing irrefutable evidence of the nature of a diamond and it provides all the information necessary to make an informed purchase.

What Questions Should You Ask About the Diamond Certification?

Diamond Certification GIA

Good question. I’m glad you asked!

Who is the certification from?

Why this one single question? Because there are several different labs that grade diamonds, such as the GIA (Gemological Institute of America), the IGI (International Gemological Institute), the EGL (European Gemological Laboratory), and the AGS (American Gemological Society). What you don’t want is a Diamond Certificate that comes from the retailer or e-tailer you bought it from. Remember, the Diamond Certificate is by an independent third party.

Now, ask yourself why someone would not use an independent third-party diamond lab? The reason is because the quality of the diamonds is lower, and many times, the grading reports can be inflated and biased to make the diamond look better on paper. Remember, there are no deals when you are dealing with diamonds.  

Gemologists that have been trained properly use specialized equipment to measure the weight and dimensions of the diamond and assess the characteristics, such as cut, color, and clarity. And these are all very important factors when you buy a diamond.

How to Read and Interpret a Diamond Certificate

How to read a diamond certificate

For our purposes, we are going to use a GIA diamond certificate or grading report because they are considered the world leader in unbiased diamond rating and grading. In fact, they set the industry standard for diamond quality by creating the scale for cut, color, clarity, and carat to act as the go-to guide for all jewelers and appraisers.

If your certification is from another appraiser that is considered ‘in-house’, consider taking your diamond to a GIA certified appraiser to make sure you got what you paid for.

Date and Certificate Number – Look for these on the top left-hand side of the certificate. This will give insight into the age of diamond. Remember, diamonds don’t age, but this tells you if the stone was used by someone else, and just means there could be some standard wear and tear on the diamond.

The certificate number is unique to each diamond. It’s the VIN for a diamond. Only some diamonds will have this number laser inscribed on the girdle of the stone, this is a common practice, but is not always done and if it isn’t done, it doesn’t affect the cost or quality of the stone. But, if it is, you can then match the VIN on the diamond to the VIN on the certificate.  The laser inscription will also help you if your diamond is stolen. To see if your diamond has a laser inscription look on the bottom of the diamond certification report under additional grading information.

Grading Results – This is where you will find the color, clarity, and shape and cut grade (for a round brilliant cut diamond only). Fancy cut diamonds never have a cut grade. This is where you also find the measurements of your diamond to the nearest hundredth of a millimeter. The grading results also include the carat weight, which describes the weight of the stone measured to the hundredth of a carat. The color of the diamond, and the clarity, which is determined by examining the stone under 10X magnification for inclusions and imperfections.

Next, you will find information on the finish of the diamond. This is influenced by polish and symmetry. These ratings assigned here are all about the diamond’s appearance. The polish indicated how smooth the diamond’s surface is. The symmetry is the comparison of how the stone’s facets are shaped, positioned and aligned in relation to one another. Next, the diamond certificate describes the diamond’s fluorescence, which is based on the intensity and the color it glows when to exposed to UV light.

Finally, you will find a clarity diagram or plot diagram, which is a graphic representation of the diamond’s markings. Blemishes (external) are marked in green color while inclusions (internal) are marked in red.

Profile of the Diamond – This is the most difficult and most important part of the diamond certificate. This is where you will find a profile diagram of the stone showing measurements. This will give you the exact proportions as a means of a percentage of the entire stone.

The two most important numbers to consider are the depth% and table %. Those measurements tell you how well the diamond is cut and how well it is likely to sparkle. The depth % is the number is from bottom of the girdle to the culet. The table % is the number is measured from the top of the stone from one side of the facet to the other.

Diamond Proportions

Security Features – Security features can help prove the authenticity of the document. Typically, these security marks come in the form of a hologram, a universal product code or an embossed stamp.

In Conclusion

Knowledge is power, and we want to provide you with all the knowledge you need to understand the diamond you want to purchase. If you are in the market to purchase a diamond, Jonathan’s Fine Jewelers has all shapes and sizes of diamonds at wholesale prices. Please contact us if you would like to either buy a certified diamond or have one to sell.

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