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Diamond grading system 101

Diamond grading system 101

Diamonds are a girl's best friend for a reason. The radiance and sparkle of diamonds make them the most sought-after style of engagement ring. However, a diamond's cut grade has a lot to do with the gem's aesthetic, because it determines how the facets interact with light. The diamond cut is crucial to the value and overall beauty of the stone. So how are you to know if you are choosing the correct custom engagement ring? Follow our breakdown of the diamond cut grading system and what to look for in the shape of your diamond:

What are the 4Cs?

Each diamond is graded on its cut, color, clarity and carat weight. In the 1950s, the Gemological Institute of America (GIA) created the International Diamond Grading System to ensure that you are aware of the diamond cut you are purchasing. The 4Cs were determined the best ways to assess the quality of cut.

Diamond components

Every diamond is comprised of five components, all of which need to be precisely cut in order to bounce enough light. The table, or the flat surface that is exposed on top of the diamond, is the largest facet of the gem. The crown is the angled portion on the top of the gem, which extends from the girdle to the table. The girdle is where the crown and pavilion meet. This area defines the perimeter of the diamond. The bottom angled portion of the diamond is the pavilion, which needs to be the proper length in order to let light in and reflect in back through the crown. A pavilion too shallow or too deep will allow light to escape, making it sparkle much less. Then, the bottom point is the culet.

Grading system

The American Gem Society created a 0-10 grading scale for diamonds based on their color. The highest grade is zero, and 10 is the lowest. Diamonds with less color are rarer, so the lower the grade, the more you are likely required to spend on the stone. However, this also means that a diamond with a low grade is more brilliant. If a diamond cut is colorless, free of blemishes and inclusions, and weights one carat, the grade will looks as follows: 0/0/0-1.000 carat.

GIA also has a grading scale, and is one of the most widely used in the industry. This scale is graded from D to Z, D being a colorless diamond cut.

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