Inclusions are ranked on a scale of perfection, or clarity, which ranges from FL (No visible characteristics under magnification), to I (Characteristics visible with the naked eye). This grading method rates diamonds on the size, nature and positioning of the birthmarks and requires an expert eye to assess.
To view inclusions, trained gemologists use a magnifying loupe. This tool allows our experts to see a diamond at 10x its actual size. 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.
As with real birthmarks, 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.