Grading Diamonds Beyond The 4 C’s

In the diamond world the 4 C’s are very common terms used to break down the grading of a diamond. Cut, Clarity, Color and Carat Weight are very important characteristics to focus on when diamond shopping, however there are several other characteristics that are often forgotten (or purposely avoided).

Some other grading terms used for diamond grading that you might have heard about but aren’t too familiar with are fluorescence, symmetry, and polish. When buying a GIA certified diamond, these features are always included on the GIA grading report, along with the 4 C’s.

The fluorescence property of diamonds is one that can be a bit confusing, because it sounds like the type of word you would want to describe your diamond. However, in general you want to strive for finding a diamond that has little to no fluorescence. Fluorescence is the color and intensity of the color the diamond glows when exposed to ultraviolet light. When you purchase a diamond outside of the none to faint range it will create a milky or greasy like cloud throughout the entire diamond, causing it look white, and lose luster. It is important to always remember when shopping for a diamond that you are looking for a diamond that is colorless and refracts the rainbow well!

Symmetry refers to how the stone’s facets are shaped and positioned in relation to one another. A diamond that is not symmetrical will have visible unevenness and reduced brilliance due to misdirected light, creating a disproportionate look. It’s important to search for a diamond that has a very good to excellent symmetry grade.

Lastly, polish describes how smooth the diamond’s surface is. A well polished diamond clearly shows reflection and non-distorted light transmission, in other words, a well polished diamond makes for a very sparkly diamond. A diamond that is poorly polished can look dull and also highlight other features of the diamond that may not be perfect.

Want to learn more about what goes into diamond grading?

Diamond with excellent cut, symmetry and polish.
This diamond was graded excellent cut, excellent symmetry, excellent polish and fluorescence none.


What Fluorescence means in Diamonds
This is a chart that shows more closely what it means for a diamond to have fluorescence.