Understanding Anatomy (Parts) of a Diamond

There’s tons of stuff on the Internet on the 4C’s Quality meters – CutColorClarity and Carat. But what does it all applies to? Understanding diamond terms and the parts of a diamond can help you apply these quality indicators and shop wisely for this precious stone. This guide is all about these physical characteristics of a real diamond.
The parts of a diamond are roughly divided into three groups : Crown , Girdle and Pavilion.

The girdle of a diamond

Diamond Girdle

The Girdle, is the outer edge of a diamond. It is that thin middle section that’s sometimes least noticeable on a diamond or gemstone. This part of a diamond is sometimes faceted and sometimes smooth.

Girdle Diameter

A diamond’s girdle diameter is the measurement of a diamond, in millimeters, of the widest point of the diamond.

The crown of a diamond

Diamond Crown

The upper portion of a diamond, above the Girdle, is the Crown. This part of the diamond consists of four additional components: table, star facets, bezel facets, and upper girdle facets.

  • The Table is the very top part of the real diamond which is completely flat. The table runs parallel to the girdle but is in fact not really a part of the crown.
  • The Star facets are right next to the table. These direct the light that goes into the diamond. The bezel facets also direct the light. These are shaped like kites.
  • Last, there is the Upper Girdle Facets. As their name suggests, these are next to the girdle. They are also the lowest facets in the crown.


The table facet is the largest diamond facet. Located at the very top of the real diamond, the table often contributes to a large percent of a diamond’s brilliance and sparkle. This is where light enters and exits the diamond – reflecting and refracting off the other facets.

In most diamond cuts, a larger table will increase brilliance but reduce sparkle. Diamond cuts with a large table facet – like the emerald cut – also carry more of their weight on top so you can get a bigger diamond for a lower price. However, diamonds with large table facets need to have excellent clarity values because inner inclusions in the diamonds will be readily seen.


A real diamond facet is any smooth cut edge on a diamond. Cutting a diamond with symmetrical facets contributes to its brilliant and shine. Facets on diamond cuts include:

The Table Facet on the top of the real diamond (see above).

Star Facets

These facets connect to the table on the top of the diamond and create a star-shaped effect (particularly in brilliant cut diamonds).

Kite Facets

Also known as a bezel facet, the kite facet, named so because it is the shape of a kite, connects the girdle to the table facet.

Girdle Facets

Diamond girdle facets fill the space between any other facets connecting to the table. Facets can also be located on the girdle itself, and are generally very small.

Pavilion Facets

These often elongated facets connect from the center girdle to the very bottom culet facet of a diamond.

The Culet Facet

This is the very bottom facet of a diamond, and it is only located on diamonds which come to a pointed tip at the bottom. Many diamond cuts, including the emerald, princess and radiant cut, do not have a culet.

The pavilion of a diamond

Diamond Pavillion

The Pavilion is the part of the diamond below the girdle. This part also has its own components. The first subject is the lower girdle facets. These are similar to the upper girdle facets. But they are below the girdle. These facets redirect the light that enters the diamond and send it back to the crown. Complementing them are pavilion facets.
They are adjacent to the culet: the final consentient part of a diamond. The Pavilion Facets redirect the light back to the crown. This is all completed with the culet, sitting at the bottom of the pavilion.

When discussing the anatomy of a diamonds, you should also take key some measurements into account.

Starting with the diamond’s length and width. Both are stated in millimeters, but the number of facets is not the only thing that matters. Their ratio is important as well. The ratio is calculated by dividing the length by the width. A diamond with exactly the same length and width (= either a perfectly square or round diamond) has an L/W ratio of 1. The girdle width determines the diamond’s class on a special scale from ‘extremely thin’ to ‘extremely with’. The culet is a single point or even a small facet.

More Diamond Terms

These real diamond terms are found on most diamond certification reports from reputable and respected gemological laboratories, and they have a lot to do with the sparkle, brilliance and cut qualities of a diamond.


The depth of a diamond is the measurement of a diamond, in millimeters, from the table to the culet.


The symmetry of a diamond is the quality of its facets and how they are cut, shaped and arranged together. Diamond symmetry is often graded from Excellent to Very Good to Good and then to down to Fair, Poor, Very Poor and Extremely Poor. For first-rate diamonds, it is best to stick with diamonds that are rated Good and above on symmetry.


The polish of a diamond can affect its brilliance and fire. Polish is an assessment of the finished outer surface of the diamond. Are there polish lines, scratches, pits or nicks? A poor polish will affect not only the brilliance and sparkle of a diamond but its cut grade and value too. On a diamond certificate grade report, diamond polish is graded like symmetry from Excellent to Extremely Poor.


The finish of a diamond is the total assessment of its polish and symmetry qualities. This final assessment can have a big impact on the cut grade of a diamond, and it is one of the most important diamond terms which you will find on a diamond certification report.


Any area of a diamond that absorbs light instead of reflecting the light back out is an area that has leakage.
One of the main aspects of studying and calculating the best diamond cutting methods involves minimizing leakage – as diamonds with a low amount of leakage have a higher amount of sparkle and brilliance. Diamonds with poor cuts can display undesirable leakage qualities.

Bow-Tie Effect

A diamond bow-tie effect is a shadowy area which appears on a diamond when looking directly down at the diamond – and this shadowy area often resembles the shape of a bow-tie.
Some types of fancy diamond cuts will exhibit a bow-tie effect, but excellent cuts will greatly minimize this effect while poor cuts will intensity the bow-tie. Fancy diamond cuts that have some type of bow-tie effect include pear, marquise, oval and heart cuts. But again, these types of fancy diamond cuts will have a very minimal bow-tie effect that might not even be noticeable at all if the cut grades on the diamonds are excellent.


The scintillation of a diamond is the sparkle that is seen when a diamond is in motion. Scintillation is a highly valued characteristic and is affected by the quality of the diamond’s cut. Some types of diamond cuts too display a higher amount of scintillation.

The cuts that generally exhibit the most scintillation include the brilliant round, the princess, the marquise, the Asscher and the radiant cut. Diamond cuts with a lower amount of scintillation include the emerald and the cushion cut.

There are two types of diamond scintillation: flash scintillation and fire scintillation. Flash scintillation is the ‘white sparkles’ seen when a diamond is in movement and fire scintillation is the ‘colored sparkles’ that appear when a diamond is in movement.

Now that you are familiar with diamond terms, diamond anatomy and the parts of a diamond, check-out our Blog on 4Cs and more.

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