Clarity
The clarity of a diamond refers to the inclusions, blemishes, flaws and imperfections a diamond contains within the stone. Inclusions have different characteristics. They can be crystals of a foreign material or another diamond crystal, or structural imperfections like tiny cracks that appear whitish or cloudy. Not only can the clarity of a diamond dramatically affect the price of a stone, but clarity also plays an important role in the brilliance/fire of a diamond.
The clarity grade is assigned based on the overall appearance of the diamond under 10x magnification (ten times the sight of a human eye). The number, size, color, location, orientation, and visibility of inclusions all affect the clarity grade of a diamond. Therefore, it is possible that you may prefer a clarity grade of lesser quality in some cases because the type or location of the inclusion does not suit you. For example, when comparing a VS2 clarity diamond that has one tiny black carbon spot underneath the table and is visible to the naked eye to an SI1 clarity diamond that has several clear inclusions that are located in the crown of the diamond but are not visible to the naked eye, a consumer may prefer to opt with the SI1 clarity diamond. Please refer to the inclusion plot on a diamond's certificate to further assist you with identifying the clarity grade that is best for you.
Most inclusions present in diamonds do not affect a diamond's structural integrity. However, clouds can affect a diamond's ability to transmit and scatter light, which reduces the diamond's fire and brilliance. Large cracks close to or breaking the surface may reduce a diamond's resistance to fracture.
Diamonds with higher clarity grades are more valued, although minor inclusions are helpful because each inclusion is unique and can be used to identify one diamond from another.