Nature being what it is, diamonds may show peculiarities of crystallization, which could be minute traces of other minerals trapped during the crystallization process. These may show up as tiny black or white marks. These natural characteristics are called “inclusions- nature's fingerprints. The number, size and position of any inclusions determine the CLARITY of a diamond. The fewer the inclusions the rarer it will be, so making it more valuable. Since it is very rare to find a diamond that's flawless the greater the value.
As with COLOR, there are internationally agreed and accepted standards of CLARITY. The major categories from the G.I.A and C.I.B.J.O systems of clarity are shown below.
C. I. B. J. O G. I. A
VVS1-VVS2- Very, very small inclusions, Very, very slightly included
VS1- VS2- Very small inclusions, Very slightly included.
SI1-SI2- Small inclusions, slightly incuded
I1- Pique1, Imperfect 1
I2- Pique2, Imperfect2
P3 I3-Pique3, Imperfect3