Diamond Clarity is a measure of a diamond's internal flaws and impurities. A diamond that is virtually free of interior or exterior inclusions (commonly referred to as flaws) is of the highest quality, for nothing interferes with the passage of light through the diamond.
To determine a diamond's clarity, it is viewed under 10x magnification by a trained gemologist. Inclusions found on a diamond can be considered nature's birthmarks, the distinguishing characteristics that make the stone unique. When grading a diamond, the amount of inclusions and blemishes has a direct impact on its clarity and value. Flawless diamonds containing no inclusions are extremely rare and expensive. A majority of commercially sold diamonds contain inclusions that are undetectable to the unaided eye.
In addition to developing and implementing the color scale, GIA also developed a scale for diamond clarity. This was done to create consistency within the industry. The GIA clarity scale consists of 11 grades ranging from Flawless to Included (Pique).
Diamonds with clarity ratings of P1 or higher contain inclusions that are typically undetectable without special magnification..