Diamonds have internal features, called inclusions, and surface irregularities, called blemishes.  Together, they are called clarity characteristics. Clarity is the relative absence of inclusions and blemishes.  

Among other things, blemishes include scratches and nicks on a diamond’s surface.  Inclusions are generally on the inside, and some might break the surface of the stone.

Clarity’s influence on value is directly related to the concept of rarity.  Flawless is the top grade in the GIA Clarity Grading System.  There are 11 clarity grades in the GIA clarity grading system.  They are Flawless, Internally Flawless, two categories of Very, Very Slightly Included, two categories of Slightly Included, and three categories of Included.


Flawless diamonds are very rare—so rare, in fact, that it’s possible to spend a lifetime in the jewellery industry without ever seeing one, and they command top prices.  At the other end of the scale are diamonds with inclusions that can be easily seen by the unaided eye.

Between the two extremes are diamonds with inclusions visible only under 10X magnification.  Stones in the middle range make up the bulk of the retail market.