Clarity refers to how ‘clean’ a diamond is, or in other words, if there are – or are not – inclusions present in the stone. Inclusions can be anything from black bits of carbon to tiny crystals of other minerals to little feather-like marks. Inclusions are actually a good thing because they can serve two purposes. Once you know the inclusions of your particular diamond they can be used as an identifier. Also, the presence of inclusions indicate the natural origin of your stone.
The scale begins with Flawless (F) and Internally Flawless (IF) which are very rare grades. Next is the Very, Very Slightly Included (VVS) category which have inclusions so small even a diamond grader has trouble seeing them. At the Very Slightly Included (VVS) category inclusions can be seen at 10 times magnification but they are very minor in comparison to the Slightly Included category (SI) where the inclusions can be seen quite clearly at 10 times magnification. Often the SI category is referred to as ‘eye clean’. Finally the Included cateogry (I) will have inclusions that are visible to the naked eye. I see the most value and quality in stones graded SI and above.
G.I.A. Clarity Scale