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How to read a certificate ?

Before offering your jewels or diamonds for sale, it is important that you understand the quality of your stones as well as the details that gives it its value. This way, you know if you are getting a decent price and you can make sure you make an honest deal.


There are many factors that determine the value of a diamond or gemstone. One of the easiest ways is to understand your certificate and how your stone has been certified.

There are several reputable laboratories and one of them is the Gemological Institute of America (GIA), which is the world's leading laboratory. There is also others certificate laboratories as HRD or IGI for diamonds and Gübelin or SSEF, which are specialized in the certification of colored stone other than diamonds.


We will help you decode a GIA certificate so that you can make sure you get the best value for your diamond!


Here are the important points that make up your certificate:


Often GIA certified diamonds have their laser engraved certificate number on the girdle rondist. This number must match the certificate number you have in your hands. In case the number is not the same, it means that you do not have the correct certificate in your hands.


The certificate informs you of the shape of your diamond. There are many different shapes for a diamond such as: round, pear, cushion, princess, radiant, and many more.

The shape of the stone refers to the arrangement of facets on the diamond. Facets are the flat surfaces that you can see on your diamond by looking at it closely.


The certificate always informs you of the measurement of your diamond. For round diamonds, measurements are presented in the following format: minimum width - maximum width x depth. 


Diamonds of other than round shape are measured by their length x width x depth.

It's measurements are calculated to the hundredth of a millimeter, so they are extremely accurate. You can know the exact size and dimensions of your diamond by comparing your measurement on your stone with that shown on your certificate.


The weight of your diamond is always indicated in carat. To calculate his carat, the diamond was weighed in the thousandth of a carat with a very precise digital measuring device. It is always indicated to the hundredth on the certificate.
For example, a two-carat diamond weighs about the weight of a small paperclip.


The color of a diamond determines the amount of yellow present in the stone. The ideal color of a diamond is "colorless", which means that the stone does not have a yellow hue at all.

There is a scale to classify the color of diamonds in relation to each other. Color control stones ranging from D to Z can be used to compare the color of a diamond with the color of another diamond in order to determine its color.

The color scale goes from D to Z, where D is the whitest color for a diamond.


The level of purity of a diamond depends on the number of its inclusions, the nature of its inclusions, the size of its inclusions and the position of inclusions in the stone.

Some inclusions can be seen with the naked eye, but often it is necessary to use a 10x magnification magnifying glass in order to properly determine the inclusions and imperfections that there is in the stone.

Purity is determined on a scale from "IF (Internally Flawless)" to "I3" (piqued). "IF" means that there are no visible inclusions in the stone after examining it with the magnifying glass. It is the highest clarity for a diamond. "I3" means that the inclusions are visible to the naked eye.

7. CUT

The size of the diamond represents how the facets were cut and how they work to reflect the light. It is the diamond factor that has the most importance on the brilliance, brightness and beauty of a diamond.

A diamond of perfect size has a distinctive and huge light return, called fire. In contrast, a diamond with a medium or low size does not reflect much light and will be considered flat and lifeless.

Size is an important factor on the value of your diamond.


The polishing of a diamond refers to its finish and how at the symmetrical level, or evenly, the facets were placed on the surface.


The fluorescence of your diamond is its reaction to long-wave ultraviolet radiation. The fluorescence of a diamond varies from zero to very strong. A diamond without fluorescence is more valuable than a diamond with.


The comments section on all diamond certificates is a place used to record all the characteristics

Our experts are at your disposal for free evaluation!

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