Diamond clarity is the quality of diamonds that relates to the existence and visual appearance of internal characteristics of a diamond called inclusions , and surface defects, called blemishes . Clarity is one of the four Cs of diamond grading, the others being carat , color , and cut .
Clarity determines how clean a diamond is. Nearly all diamonds, lab-grown and mined alike, have inclusions. These are imperfections that contribute to the overall uniqueness of a diamond, and commonly consist of crystals, feathers, clouds and trace minerals in mined diamonds, and trace metals in lab-grown diamonds.