As a product of nature diamonds may bear traces of the pressure and processes involved in their formation. These traces may appear on the diamond either externally or internally, and are referred to as "inclusions". When referring to "diamond clarity", we are referring to the amount of and type of inclusions found in the diamond.
Where appearing internally on the diamond these inclusions may include air bubbles, cracks and non-diamond mineral deposits. Inclusions appearing externally may include scratches, pits and chips.
Not all diamonds have inclusions, and those without are rare and usually the most expensive. These diamonds would receive the highest clarity grading of FL (No internal or external flaws). Diamonds are clarity graded according to the amount of inclusions detected, with and without magnification.
Inspection for clarity grading occurs under 10x magnification. Grading is allocated to a range of diamonds from "Flawless" to "Included-3".
Diamond clarity grades:
- FL (Flawless):
No internal or external flaws;
- IF (Internally Flawless) or LC (Loupe Clean):
No internal flaws but some surface flaws;
- VVS1-VVS2 (Very Very Slightly Included):
Tiny inclusions which are very difficult to detect under 10x magnification;
- VS1-VS2 (Very Slightly Included):
Tiny inclusions which are difficult to detect under 10x magnification;
- SI1-SI2 (Slightly Included):
Tiny inclusions which are detectable under 10x magnification, and sometimes possible to detect by the naked eye;
- I1-I3 (Included):
These inclusions are detectable under 10x magnification, and are also visible to the naked eye.
Each diamond's inclusions are unique to that diamond, with no two diamonds displaying the exact same inclusions. The Gemological Institute of America (GIA) diamond grading reports include graphic illustrations of inclusions found in diamonds. These graphic illustrations match the inclusions actually found in the diamonds, providing each diamond with its own "diamond fingerprint".