Diamond clarity grading...

Naturally-occurring features called inclusions provide a special fingerprint within the stone. Inclusions are natural identifying characteristics such as minerals or fractures, occurring while the diamond was being formed in the Earth.

 The majority of these natural birthmarks are invisible to the naked eye, yet they affect the way light is reflected and refracted within the stone. Inclusions appear as different shapes, such as crystals, clouds or feathers. These idiosyncrasies often add to the overall character of the diamond.
Containing several birthmarks or inclusions, the Excelsior is considered one on the world's most beautiful diamonds.

Most inclusions are not visible to the naked eye unless magnified. To view inclusions, gemmologists use a magnifying loupe that allows them to see a diamond at 10x its actual size.

Inclusions are ranked on a scale of perfection, known as clarity.  The clarity scale, ranging from F (Flawless) to Included (I), is based on the visibility of inclusions at a magnification of 10x. 
Even with a loupe, the birthmarks in the VVS (Very, Very Slightly Included) to VS (Very Slightly Included) range can be very difficult to find. It is only when a diamond is graded 'I' that it is possible to see the birthmarks with the naked eye.
The position of inclusions can affect the value of a diamond and you should consider the number, size, brightness, nature and position of inclusions. Some inclusions can be hidden by a mounting, and have little effect on the beauty or brilliance of a stone. An inclusion in the middle or top of a diamond could impact the dispersion of light, sometimes making the diamond less brilliant.

There are very few flawless diamonds found in nature, making these diamonds much more valuable. 

All of the grades of diamond clarity shown in the table below, reflect the appearance of inclusions within the stone when viewed from above at 10x magnification Higher magnifications and viewing from other angles are also used during the grading process. In "colorless" diamonds, darker inclusions will tend to create the most significant drop in clarity grade. In fancy-colored diamonds, light or pale inclusions may show greater relief, making them more apparent, causing a greater drop in grade.

 Diamond Clarity Designations


  • FL - "Flawless" no inclusions at 10 x magnification
  • IF - "Internally Flawless" no inclusions at 10 x mag. - small blemishes
  • VVS-1 - "Very Very Small" inclusions hard to see at 10 x magnification
  • VVS-2 - "Very Very Small" inclusions. VVS1 better than VVS2
  • VS-1 - "Very Small" inclusions visible at 10 x mag. - not naked eye
  • VS-2 - "Very Small" inclusions VS1 is better grade than VS2
  • SI-1 - "Small" or "Slight" Inclusions or "Imperfections" may be "eye clean"
  • SI-2 - "Small" or "Slight" Inclusions or "Imperfections" visible to naked eye
  • SI-3 - Inclusions large and obvious, little or no brilliance
  • I1 to I3 - Imperfect, with large Inclusions, fractures, and flaws






Free from all inclusions or blemishes.


Internally Flawless

No inclusions visible at 10X magnification.


Very Very Slightly Included. (#1 inclusion.)

Inclusions that are extremely difficult to locate at 10X.


Very Very Slightly Included. (#2 inclusions.)

Inclusions that are very difficult to locate at 10X.


Very Slightly Included. (#1 inclusion.)

Minor inclusions that are difficult to locate at 10X.


Very Slightly Included. (#2 inclusions.)

Minor inclusions that are somewhat difficult to locate at 10X.


Slightly Included. (#1 inclusion.)

Noticeable inclusions that are easy to locate at 10X.


Slightly Included. (#2 inclusions.)

Noticeable inclusions that are very easy to locate at 10X.


Included. (#1 inclusion.)

Obvious inclusions. Somewhat easy to locate with the unaided eye.


Included. (#2 inclusions.)

Obvious inclusions. Easy to locate with the unaided eye.


Included. (#3 inclusions.)

Obvious inclusions. Very easy to locate with the unaided eye.

GIA Grading System

The chart in Fig. 1 explains the GIA grading system for inclusions and imperfections. Considerations in grading the clarity of a diamond include the type of stone, point size and the location of inclusions. Inclusions that are near to, or break the surface, may weaken the diamond structurally, therefore reducing its value significantly. On the other hand, it may be possible to hide certain inclusions behind the setting of the diamond (depending on where the inclusion is located), thus minimizing any negative impact of the inclusion.

Fig. 1