Type to search

Education Fashion Jewelry

What Is the Girdle of a diamond? | Complete Jewelry Guide

What is a Diamond Girdle by Bixler

The girdle is the thin perimeter on a diamond that divides the upper crown from the below pavilion. When looking at a diamond from a profile view or from its setting, the circumference (& widest area) of a polished diamond is the girdle. It is the part of the gem that connects with the setting of the stone. Usually, a loose diamond is measured by its girdle in order to determine its size in millimeters. The girdle of a diamond can be faceted, polished, or bruted. A brilliantly cut diamond generally has a faceted girdle instead of a completely round girdle, to give the stone an intense level of transparency. Usually, a certified diamond is measured at different points around its girdle in order to determine the thinnest and thickest points. To learn more about the girdle of a diamond, read on.

What Girdle Is Best for a Diamond?

When it comes to the girdle of a diamond, what you’d consider ‘best’ is relative because it depends on a lot of factors. However, there is a standard that you can work with. The best way to view the diamond girdle is through the Excellent Diamond Proportions scale developed by GIA (Gemological Institute of America – an independent not-for-profit organization based out of USA)

RELATED: Bixler’s Complete Diamond Guide

The GIA uses an eight-grade scale for diamond girdle. These grades are Extremely Thin, Very Thin, Thin, Medium, Slightly Thick, Thick, Very Thick, and Extremely Thick. According to the GIA, the best is either the Thin, the Medium, or Slightly Thick. Any diamond girdle that falls within these three ratings will fit perfectly into the Excellent Grade rating. You should avoid girdles that are Extremely Thick, Very Thick, or Extremely Thin.

The Girdle of a Diamond among with the other important parts of it

What Difference Does a Diamond’s Girdle Make?

Well, the major factor that determines how important a diamond girdle is is the cut of the diamond. For instance, if you are buying a round cut diamond, you should be concerned about the girdle. This is because a girdle has a direct effect on the cut grade of your chosen diamond. However, if you are contemplating buying a fancy-shaped diamond, the girdle doesn’t really have much impact on your piece and you don’t have to give it as much consideration.

RELATED: Browse Diamond Jewelry from America’s Oldest Jeweler

The girdle holds the diamond in place on a piece of jewelry. Therefore, if it is too thin, the biggest concern is chipping or breaking. On the flip side, an extremely thick girdle may indicate that there is too much carat weight at the center of the diamond piece, which gives it too much depth. The implication of this is that the diamond will appear smaller than its actual carat weight. In addition to this, the girdle may produce a grey reflection on the diamond, thus diminishing the brilliance and sparkle of the diamond, making it look dull in appearance.

Why Is It Important?

While this part of the diamond is almost unnoticeable, it is one of the most important features of a polished diamond. The quality of the cut and the durability of a piece are both significantly affected by it. It also plays a vital role in the symmetry grading of a piece of diamond. Normally, the symmetry grade provided by a laboratory is an assessment of the consistency with which the facets meet at certain spots on the diamond. To establish the grade, the girdle is carefully inspected to determine consistency in the arrangement of the crown and pavilion facets.

Diamond Girdle - What is a diamond girdle by Bixler

The girdle also has another important role, which is acting as a safety barrier or protection against any form of damage to the diamond’s edge during its setting and daily wear. The extremely thin girdles can make the gem more susceptible to chipping and abrasion. It’s also the perfect location to place a subtle laser inscription on the diamond. This helps with identification without tampering with the appearance or beauty of the diamond. No doubt, the girdle of a diamond is quite important and should be kept in mind when buying one.

What Are the Different Diamond Girdle Types?

There are three types of diamond girdles that a full-cut diamond can have. These are Faceted, Polished, and Bruted.


This is the most common amongst all girdle types. It is cut and polished like the remaining parts of the diamond. You don’t notice a faceted girdle because it mirrors light and seamlessly blends with the rest of the gem.


A polished girdle is clean and smooth with no roughness or facets all the way around the diamond piece. The clean strip circles the exterior perimeter of the gem and it doesn’t trap dirt or accentuate flaws. They are also not distracting but can be slippery and pop out fast when being handled separately.


A bruted girdle is an actual diamond in its rough, natural, raw, unpolished, and untouched state. It is the exact look of a diamond before it goes through the cutting and polishing process. A bruted girdle may look rough, white, frosty, and grainy. This is usually not an issue of concern.


Leave a Comment

Your email address will not be published. Required fields are marked *

Subscribe To Newsletter
Be the first to get latest updates and exclusive content straight to your email inbox.
Stay Updated
Give it a try, you can unsubscribe anytime.